Multiple Histograms

A histogram is very similar to a bar chart. The bars of a histogram are also vertical, but unlike a bar graph and there are no gaps between the bars. Also, the data must be grouped into class intervals of equal width. The histogram which can be used to display a given data. This is called a histogram. A histogram is a bar graph in which the bars touch. The vertical axis represents frequencies, the horizontal axis represents classes.

Types of multiple histogram

There are 3 types of histograms:
1. 1p Histograms
2. 2p Histograms
3. 3p Histograms

Window to create the multiple histograms:

Construction of a Multiple Histogram:

  The steps below are used to create the multiple histograms These are the fast and efficient steps to have the multiple histograms.

      Step 1: Select the 1p histograms. The parameter on x axis must be selected and add to  the list.

      Step 2: In 2p histograms. The one more axis must be selected that is nothing but y axis and x axis. If we need side scatter and forward scatter select it on y axis.The add to the list button

     Step 3: The 3p histograms is similar to 2p histograms.

     Step 4: The combination mode is available in 2p histogram alone. The combination mode is to see the possible plots by the possible of set of parameters. The y axis is grayed out.

     Step 5: If the above process gets over then click the ok button to generate the histograms.

    Step 6: The cancel button is used  to close the creation of the histogram

   Step 7: The delete button is used to erase the selected items in the histograms lists.

   Step 8: The resolution is used to select the items which are going to add on the list below.

These are the steps to have the generation of multiple histograms.

Examples for multiple histograms:

Calculus Formula Sheet

Calculus is a branch in mathematics which deals with the study of limits, functions, derivatives, integrals, and infinite series. It has two main branches

• Differential calculus
• Integral calculus

It is a formula sheet which contains differentiation and integration formulas which are needed to solve the calculus problems. We should know all the calculus formulas before get into the problems. Calculus formula sheet helps you to learn all those formulas. It is very much helpful for the students at the time of examination for reviewing calculus formulas.

Integration is a limiting process which is used to find the area of a region under a curve.  We can also say that integration is an anti derivative of differentiation. Integration of a function is shown as,
int` f(x) dx = F(x) + C
int `  = Sign of integration
The variable x in dx is called variable of integration or integrator.
C= constant          

Differential calculus formula sheet:

Derivatives of polynomial functions:
`d/dx` (c) = 0
`d/dx` (x) = 1
`d/dx ` (cx) = c
`d/dx` (xⁿ) = nx^n-1
`d/dx` (cxⁿ) = ncx^n-1

Derivatives of trigonometric functions:
`d/dx` (sin x) = cos x
`d/dx` (cos x) =  - sin x
`d/dx ` (tan x) = sec² x
`d/dx` (cot x) = - cosec²x
`d/dx` (sec x) = sec x tan x
`d/dx` (cosec x) = - cosec x cot x

Derivatives of inverse trigonometric functions:
`d/dx` (sin^-1 x) = `1/sqrt(1 - x^2)`
`d/dx` (cos^-1 x) = - `1/sqrt(1 - x^2)`
`d/dx` (tan^-1 x) = `1/(1 + x^2)`
`d/dx` (sec^-1 x) = `1/(|x|sqrt(x^2 - 1))`
`d/dx` (cosec^-1 x) = - `1/(|x|sqrt(x^2 - 1))`
`d/dx` (cot^-1 x) = - `1/(1 + x^2)`

Derivatives of hyperbolic functions:
`d/dx` (sinh x) = cos hx
`d/dx ` (cosh x) = sin hx
`d/dx ` (tanh x) = sec h²x
`d/dx` (sech x) = - tanh x sech x
`d/dx` (cosech x) = - coth x cosech x
`d/dx` (coth x) = - cosech²x

Integral calculus formula sheet:

List of integrals of rational functions:
`int` k dx = kx + C
`int` x^a dx = `(x^(a+1))/(a+1)` + C
`int` 1/x dx = ln|x| + C

List of integrals of logarithmic functions:
`int` ln x dx = x ln x - x + C
`int ` log_ax dx = xlog_ax  - x(ln a) + C

List of integrals of exponential functions:
`int ` e^x dx = e^x + C
`int ` a^x dx = `(a^x)/(ln a)` + C

List of integrals of trigonometric functions:
`int` sin x dx = - cos x + C
`int` cos x dx  = sin x + C
`int` tan x dx  = - ln |cos x| + C
`int` cot x dx = ln |sin x| + C

Computing Ratio

A relation obtained by comparing two quantities similar in some sense is called a ratio. Ratio can be expressed in terms of fraction, that is,  a:b is equal to a/b For example 25 is 1/4^th of the hundred, Therefore, the ratio of 25 to 100is ¼. We write it in ratio as 1:4.

Facts for computing ratio:

The numbers a and b in a ratio a:b are called the term of the ratio. Here, a is called the first terms and b is called the second term of the ratio

Computing Nature of ratio:
A ratio is purely a number: it has no unit attached to it.

Computing Comparison of ratio:
Since, the ratio a:b represents what multiple are part a is of b, it is also equal to a/b.
Accordingly ratio a : b is said greater than a ratio c : d if, a/b > c/d ( b and d >0)
Or  ad – bc > 0

Computing simplest form of ratio:
Since, a/b=ma/mb for every non-zero number m, therefore the ratios a:b and ma:mb are the same.
If,a/b is in its lowest terms, the ratio a:b is said to be in its simplest form.

Computing Composition of ratios:
Two or more ratios can be compounded.
For example: the ratio compounded of the ratios.

1. 2:3 and 4:5 is 2 * 4 : 3 * 5
2. a : b  and c : d is ac : bd

Note: The ratio a : B and B : a are generally different.
For example: the ratio 3:4 is ¾ where as, the ratio, 4:3 is 4/3 and surely ¾ is not equal to 4/3

Example problem for computing ratio:

Example:

In red and green tiles, the ratio of red tiles to green tiles is 2:3. If there is 90 green tiles, how many red tiles are there?

Solution:

Step 1: Assign variables:

Let x = red tiles

Write the items in the ratio as a fraction.

Red / green = 2/3 = x / 90

Step2: Do the cross multiplication

2 * 90 = 3 * x

3 * x = 2 * 90

3x = 180

3x / 3 = 180 / 3

X = 60

Example 2:

The length and width of the rectangle is 4:3 whose perimeter is 350.Find the are of the rectangle.
Solution:
Take the ratio 4:3
Consider 4x be the length and 3x be the width.
Perimeter of the rectangle is =350
That is, 2(l+w)= 350
2(4x+3x)= 350
2*7x=350
14x=350
X=25
Therefore,
The length of the rectangle is 4x= 4*25=100.
The width of the rectangle is 3x=3*25=75

Area of the rectangle = length * width = 100 * 75 = 7500

Ellipse Line Intersection

In this article we discuss ellipse line intersection. Ellipse is a conic section of geometry function. Ellipse can be defined in mathematically a plane passing through the right circular at angle between `0^o` to `90^o` . Ellipse can be included in two points like A1, A2. These two points called  focus.                                                     

                     

We are taking any two points on an above ellipse, the sum of the distance from the focus points is constant.

Shape of the ellipse line intersection:

The intersection of line in ellipse at centered origin. The line can passing through the points is `(x_o, y_o)` or origin. 

                           

The formula for ellipse is given below,
x^2/a^2+y^2/b^2=1`
where,
a=horizontal semi- axis
b=vertical semi-axis
 The trigonometry formula for ellipse is,
x=acos(t) and
y=asin(t)
where,
t =ellipse parameter
a=horizontal axis
b=vertical axis

Some important properties of ellipse line intersection:

• Center of ellipse :                 

It can be defined as connecting the focus points by using inside the single midpoint. It is also called as intersection of major and minor axes.                                             

• Major and Minor axes:

The longest diameter of the ellipse is called as major axes and shortest diameter of the ellipse is called as minor axes.                               

                    

• Tangent:

A line just touching one point on a ellipse is called as tangent.
                                             

                

• Secant :

The intersection of two points on an ellipse is called as secant.                                                            

                    

• Chord :

It can be defined as a line just linking any 2 points on ellipse. 

Triangle Online

A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ABC. In Euclidean geometry any three non-collinear points determine a unique triangle and a unique plane. (Source: Wikipedia)

Once you've gone through these, take a look at our Equilateral Triangle Area for more refernce.

Example problems for triangle solver online

Triangle solver online example 1:
                  A triangle has the base length of 20 cm and height is 23 cm. Find the area of the triangle in cm².
Solution:
   Given, base length (b) = 20 cm and height (h) = 23 cm.
Formula:
         Area of the triangle = `(1 / 2)` * (b * h)
Substitute the given base length and height values in the above formula, we get
                                            = `(1 / 2)` * (20 cm * 23 cm)
                                            = 230 cm²
Answer:
  Area of the triangle is 230 cm²

Triangle solver online example 2:
    Find the area of the given triangle.
        
Solution:
   From the given triangle ABC,
             Base length (b) = 20 cm and height (h) = 23 cm.

Formula:
         Area of the triangle = `(1 / 2)` * (b * h)
Substitute the given base length and height values in the above formula, we get
                                            = `(1 / 2)` * (20 cm * 23 cm)
                                            = 230 cm²
Answer:
  Area of the triangle is 230 cm²

Triangle solver online example 3:
    Find the x value of the given triangle.
       
Solution:
   From the given triangle ABC,
            Angle (B) = 60° and Angle (C) = 55° and Angle (A) = x
We know,
    Sum of the angle in triangle is 180°
 Therefore,
   Angle (A) + Angle (B) + Angle (C) = 180°
Substitute the given values in the above formula, we get
              x + 60° + 55° = 180°
                      x  + 115 = 180°
Subtract 115 on both the sides, we get
                                  x = 65°
Answer:
  The final answer is Angle (A) = 65°

Triangle solver online example 4:
    Find the x value of the given triangle.
    
Solution:
       Given triangle is right triangle ABC.
From the triangle ABC,
AC = x, AB = 48, BC = 36
Using Pythagoras theorem,
           AC² = AB² + BC²
Substitute the given values in the above formula, we get
              x² = 48² + 36²
               x² = 3600
Take square root on both the sides, we get
                 x = 60
Answer:
The final answer is 60

Practice problem for triangle solver online

Triangle solver online practice problem 1:
    A triangle has the base length of 32 cm and height is 53 cm. Find the area of the triangle.
Answer:
 The area of the triangle is 848 cm²
Triangle solver online practice problem 2:
    Find the area of the given triangle.
    
Answer:
 The area of the triangle is 210cm²

Triangle solver online problem 3:
    Find the area of the given triangle.
        
Answer:

 The area of the triangle is 80 cm²

Four Sided Polygons

If polygon has 4 sides then its represented as quadilateral.A quadrilaterals is generally mentioned as four sided shape.the following are the examples for four sided polygons,they are
1.square
2. rectangle.
3.Rhombus.
4.paralellogram.
Now in this article we are going to discus about the four sided polygons, but before that take a look at some example for four sided polygons.



Please express your views of this topic Similar Polygons by commenting on blog

Description to four sided polygon:

Let us see the brief discussing about the four sided polygons:
Square:
square has four equal sides. the following properties are used in square.



Area of the square :
A = a²
where a represents the length of one side.

Perimeter of the square :
P = 4a
where a is one side length value.
angle: all the angles are right angle (90^o)
Rectangle :
The opposite sides of the rectangle is equal.


Perimeter of the rectangle:
P = l+w+l+w
where l = length
and w = width
P= 2l+2w
    = 2(l+w)

Area of the rectangle :
Area A = length and width
         = lw.
opposite angles are congruent.
opposite sides are parallel.
Length of diagonal is calculated by
d= `sqrt (l^2+w^2)`

parallelogram:
Parallelogram has four sides, and the properties are listed below



Perimeter of the parallelogram
P = a+b+a+b
 = 2a+2b.

Area of parallelogram:
The are of the parallelogram is represented as
A = base * height
 = b*h
opposites sides are same length and also parallel.
opposite angles are congruent.

Rhombus:
rhombus is a quadrilateral which has four sides, the properties are listed below.


Perimeter of Rhombus:
P = a+a+a+a
 = 4a
where a is side length of the rhombus.
Area of Rhombus:
The are of the rhombus is calculated by
A = 1/2 ab
where a and b are diagonals of the rhombus.
all the sides of the rhombus are congruent.
opposite angles are congruent.

Example problems for four sided polygons:

Let we see some practice problems for four sided polygons.
Example 1)
Find the area and perimeter of the square whose side is 5 cm
Solution:

Area of the square :

A= a²

where a = 5.

A= 5²

=5*5

=25cm²

Perimeter of square:

p = 4a

=4*5

=20 cm.

Example 2)
Find the area and the perimeter of the rectangle whose height = 6 cm and base =8 cm
Solution:

Area of the rectangle :

A = l*b

where l=6 cm and

b= 8 cm

A = 6*8

=48cm²

Perimeter of rectangle:

P = 2(l+w)

=2(6+8)

=2(14)

=28cm.

Triangular Prism Net

A triangular prism is a solid has two parallel faces which are congruent triangle at both ends. These faces form the bases of the prism

The others faces are in the shape of parallellogram.They are called lateral faces.
A right triangular prism that has its bases perpendicular to its lateral surfaces.

Once you've gone through these, take a look at our Volume of Rectangular Prism for more refernce.

Surface area of triangular prism=2base area+peripeter of base x height prism
Volume of triangular prism = Base area of prism x height of prism.

Under this concept of triangular prism we draw the triangular prism net.
 Prepare the model of triangular prism net ,we need a paper , a pencil or pen, a scissor and gum.

Method of preparing triangular prism net

 First we draw the rectangle and two triangles to two ends of the rectangle on the paper. Then cut out along solid sides.
 Fold along dotted lines.
 Use clear tape to fasten .
 If you want to draw or colour the net,do it before you tape it together.
 If you want to decorate it by gluing on decorations, tape it together first.

Quadrilateral Prism Shape

In geometry, an n-sided prism is a polyhedron made of an n-sided polygonal base, a translated copy, and n faces joining corresponding sides. Thus these joining faces are parallelograms. All cross-sections parallel to the base faces are the same (source-Wikipedia). If the prism has four sides then it is called quadrilateral prism. in this article we shall discus about some quadrilateral prism.

Quadrilateral prim shapes:

Cube:

It is one type of quadrilateral prism. Its all dimensions are equal in measure (all side are equal).it has eight vertices. The shape of the cube is shown in below.
Formula for Volume of the cube V= a3 cubic units
Where,
            V = volume of the cube
 a =side length (or edge) of the cube.
Formula for surface area of the cube (A) = 6 a² square units

Rectangle prism:

It is one type of quadrilateral prism. The shape of the cube is shown in below.
Volume of rectangular solid (V) = length x width x height Cubic units
     = l x w x h cubic unit.
Total surface area of rectangular prism
                                    = 2 (length x breadth + breadth x width + length x height)
                                    =2(lb + bh+ lh) square units

Trapezoidal prism:

It is one type of quadrilateral prism.it has one set of parallel sides. The shape of the trapezoidal prism is shown in the figure.
Volume of trapezoidal prism = l x area of the base cubic units
                                                       l – Length of trapezoidal prism
                              Area of the base= 1/2 x (a + b) x h square units
                                                       a and b are length of parallel sides.
                                                       h – Height

Quadrilateral prism shape - Example problems:

1. Find the volume and surface area of the cube whose side length is 17 cm.
Solution:
            Given:
                        Side length (a) = 17 cm
Formula:
            Volume of the cube V= a³ cubic units
                                                = 17³
                                                = 17 x 17 x 17
                                                = 4913 cm³
            Surface area of the cube (A) = 6 a² square units
                                                          = 6 x 17²
                                                          = 6 x 289
                                                          = 1734 cm²

2. Find the lateral surface area and total surface area of a rectangular whose length is 6 cm, width 3cm and height 6cm.
Solution:
Given:
                              Length (l) = 6 cm
                         Width (w) = 3 cm
                           Height (h) = 6 cm
Total surface area of rectangular prism =2(wh + lw+ lh) square units
                                                               = 2(3 x 6+ 6 x 3 +6 x 6)
                                                               = 2 (18 + 18 + 36)
                                                               = 2 (72)
                                                               = 144
Total surface area of rectangular prism = 144 cm²
            Volume of the rectangular prism (V) = l x w x h cubic units
                                                                           = 6 x 3 x 6
                                                                           = 108
                                                                           = 108 cm³
3.figure out the volume trapezoidal prism whose length 14 cm, height 5cm, length of parallel sides a=7 cm and b=4cm.
Solution:
Given:
                  Length (l) = 20 cm
                  Height (h) = 5 cm
                  Parallel sides a=7 cm and b=4 cm
Formula:
Volume of trapezoidal prism = l x area of the base cubic units

Area of the base:
Area of the base= 1/2 x (a + b) x h
                                                   = 1/2x (7 + 4) x 5
                                                   =1/2 x 11 x 5
                                                     = 27.5 cm²
Volume of trapezoidal prism = 20 x 27.5
                                                  = 550

Volume of trapezoidal prism = 550 cm³

Figuring Volume of a Structure

Volume of structure
Volume is how much three-dimensional space a substance (solid, liquid, gas, or plasma) or shape occupies. The volume of a container is generally understood to be the capacity of the container, i. e. the amount of fluid (gas or liquid) that the container could hold, rather than the amount of space the container itself displaces.
Volume is measured in "cubic" units.


Volume of Cylinder
A cylinder is a solid that has two parallel faces which are congruent circles. These faces form the bases of the cylinder. The cylinder has one curved surface. The height of the cylinder is the perpendicular distance between the two bases.
The volume of a cylinder is given by the formula:
Volume = Area of base × height

V =   r²h where r = radius of cylinder and h is the height or length of cylinder.

Volume of hollow cylinder

Volume of hollow cylinder
V=πR²h-πr²h
Where R is the radius of the outer surface and r is the radius of the inner surface.

Volume of Cone

A cone is a solid with a circular base. It has a curved surface which tapers (i.e. decreases in size) to a vertex at the top. The height of the cone is the perpendicular distance from the base to the vertex.

Volume of cone = 1/3 Area of base × height
V = 1/3πr²h where r is the radius of the base and h is the height of the prism.

Volume of Pyramid

A pyramid is a solid with a polygonal base and several triangular lateral faces. The pyramid is named after the shape of its base. For example, rectangular pyramid, triangular pyramid.
The lateral faces meet at a common vertex. The height of the pyramid is the perpendicular distance from the base to the vertex.

The volume of a pyramid is given by the formula:

Volume of pyramid =  1/3Area of base × height

V = 1/3Axh where A is the area of the base and h is the height of the pyramid.

Algebra Data Analysis Help

he Algebra data analysis is one of the important branch of algebra concerning the learn of rules of operations and dealings. The constructions and concepts arising from algebra data analysis. Algebra data analysis including terms, polynomials, expressions, quadratic formula and algebraic structures or pre-algebra structure. We will solve examples in polynomial equations and quadratic formula. This article has information about algebra data analysis help as well as examples.

Polynomial equations – Algebra Data Analysis Help:

In algebra data analysis, the polynomial equations are one of the most significant factors.
Now we will solve the polynomial problem in algebra data analysis with help of example problem.

Example Problem 1:
Solve given polynomial equations.
6x² + 4 + 9x + 3x² + 3x + 9 + 7x
Solution:
Step 1:
First we have to mingle terms x²
6x²+3x²=9x²
Step 2:
Now combine the terms x
9x + 3x + 7x = 19x
Step 3:
Then join the constants terms
4 +9 =13
Step 4:
Finally, combine all the terms
9x² + 19x +13
So, the final answer is 9x² + 19x +13

Example Problem 2:
Solve following polynomial expression.
11x² + 2 + 9x + 13x² + 5x + 4 + 3x
Solution:
Step 1:
First we have to mingle terms x²
11x²+13x²=24x²
Step 2:
Now combine the terms x
9x + 5x + 3x = 17x
Step 3:
Then join the constants terms
2 + 4 =6
Step 4:
Finally, combine all the terms
24x² + 17x +6
So, the final answer is 24x² + 17x +6

Quadratic formula - Algebra Data Analysis Help:

In algebra data analysis, quadratic equation with real or complex coefficients contains two solutions, is known as roots.
The roots are given by the quadratic formula

Example of quadratic formula:
Example Problem1:
Solve 7x² + 5x = -3.
Solution:
Now we will find the standard form for the quadratic equation and calculate a, b, and c.
7x² + 5x + 3 = 0
a = 7
b = 5
c = 3

Now applying the formula,


= `(-5 +- sqrt(5^2 - 4 xx 7 xx 3))/(2 xx 7)`
=`(-5+-(sqrt(25-84)))/(2xx7)`
=`(-5 +-(sqrt(-59)))/(14)`
=`(-5+- i 7.68)/14`
=2.68 `+-i` -7.68

Answer:
2.68 `+-i` -7.68
These are examples in algebra data analysis help.

That's all about algebra data analysis help.

Measurement of Angle

• Line joins two positions and which are nonstop in two directions. Lines have one endpoint of two lines and infinite in one direction is called angle.
•  The grouping point of two lines is called the vertex.

               

•  Angles are denoted as degrees. In measurement of angles can diverge in between 0 and 180 angles.

Concept -measurement Angle:

Concept of angles:

      There are three major categories of angles: right angle, obtuse angle, and acute angle.

• A right angle – a measurement of an angle is 90 degrees.
• An acute angle - a measurement of an angle in between 0 to 90 degrees.
• An obtuse angle - a measurement of an angle in between 90 and 180 degrees.

More about angles and measurement of angle:

More about angles:

1)      Vertical angle measurements are two angles with a common vertex and with sides that are two pairs of opposite of opposite rays. (That is, the union of the two pairs of sides is two lines.)  

                              

2)       A right angle measurements has a measure of 90^o.    

     

                       

3)      An acute angle measurement is an angle whose measure is larger than 0^o and smaller than 90^o.  

          

                

4)      An obtuse angle measurement has a measure larger than 90^o and less than 180^o.  

           

               

5)     Straight angle measurement has a measure of 180^o. The rays of a straight angle lie on a line.

6)      Complementary angle measurements are two angles, the addition of whose measures is 90^o.

               

7)      Supplementary angle measurements are two angles, the addition of whose measures is 180^o.

               

Step to measurement of angle:

          

Step 1: To find the angle is obtuse or acute before using the protractor.

          

Step 2: Position the protractor on the center mark on the vertex of the angle

          

Step 3: position the protractor, line up with one ray of the angle and another ray of the angle cross the protractor’s scale

          

Step 4: to check the measure of the angle of the line that crosses the protractor scale.

          

How to calculate volume

Example problems:

Here are some solved examples on How to calculate volume:
Problem 1:

Problem 2:
Calculate the volume of the cone with base radius = 5cm and height at the apex is 4 cm.
Solution:
Volume of a cone: (13)(π)(r2)h
                                 = (13)(π)(52)4
                                = 104.666 cm^3
Problem 3:

Problem 4:
Calculate the length of the rectangular prism, when the volume is 36 cm^3 , width = 3 m, height is = 4m
Solution:
Volume of the rectangular prism = l * w * h.
                                                     36 =  l* 4*3
                                          Therefore,  l= 3m
Students can understand How to calculate volume from the above examples and learn to solve on their own.

Parametric t Test

Conventional statistical procedures are also called parametric tests. In a parametric test a sample statistic is obtained to estimate the population parameter. Because this estimation process involves a sample, a sampling distribution, and a population, certain parametric assumptions are required to ensure all components are compatible with each other. 

For example, in Analysis of Variance (ANOVA) there are three assumptions:

• Observations are independent.
• The sample data have a normal distribution.
• Scores in different groups have homogeneous variances.

In a repeated measure design, it is assumed that the data structure conforms to the compound symmetry. A regression model assumes the absence of collinearity, the absence of auto correlation, random residuals, linearity...etc. In structural equation modeling, the data should be multivariate normal.

Why are they important? Take ANOVA as an example. ANOVA is a procedure of comparing means in terms of variance with reference to a normal distribution. The inventor of ANOVA, Sir R. A. Fisher (1935) clearly explained the relationship among the mean, the variance, and the normal distribution: "The normal distribution has only two characteristics, its mean and its variance. The mean determines the bias of our estimate, and the variance determines its precision." (p.42) It is generally known that the estimation is more precise as the variance becomes smaller and smaller.

Put it in another way: the purpose of ANOVA is to extract precise information out of bias, or to filter signal out of noise. When the data are skewed (non-normal), the means can no longer reflect the central location and thus the signal is biased. When the variances are unequal, not every group has the same level of noise and thus the comparison is invalid. More importantly, the purpose of parametric test is to make inferences from the sample statistic to the population parameter through sampling distributions.

When the assumptions are not met in the sample data, the statistic may not be a good estimation to the parameter. It is incorrect to say that the population is assumed to be normal and equal in variance, therefore the researcher demands the same properties in the sample. Actually, the population is infinite and unknown. It may or may not possess those attributes. The required assumptions are imposed on the data because those attributes are found in sampling distributions. However, very often the acquired data do not meet these assumptions. There are several alternatives to rectify this situation.