Normal distribution, Mathematics

Assignment Help:

Normal Distribution

Figure 1

1015_normal distribution.png

The normal distribution reflects the various values taken by many real life variables like the heights and weights of people or the marks of students in a large class. In all these cases a large number of observations are found to be clustered around the mean value m and their frequency drops sharply as we move away from the mean in either direction. For example, if the mean height of an adult in a city is 6 feet then a large number of adults will have heights around 6 feet. Relatively a few adults will have heights of 5 feet or 7 feet.

Further, if we draw samples of size n (where n is a fixed number over 30) from any population, then the sample mean 89_computation of covariance ungrouped data2.png   will be (approximately) normally distributed with a mean equal to m i.e. the mean of the population.

The characteristics of normal probability distribution with reference to the above figure are

  1. The curve has a single peak; thus it is unimodal.

  2. The mean of a normally distributed population lies at the center of its normal curve.

  3. Because of the symmetry of the normal probability distribution, the median and the mode of the distribution are also at the center.

  4. The two tails of the normal probability distribution extend indefinitely and never touch the horizontal axis.

If s is the standard deviation of the normal distribution, 80% of the observation will be in the interval m -1.28s to m + 1.28s.

Figure 2

375_normal distribution1.png

95% of the observations will be in the interval m - 1.96s to m + 1.96s.

Figure 3

2353_normal distribution2.png

98% of the observations will lie in the interval m - 2.33 s to m + 2.33 s.

Figure 4

342_normal distribution3.png

 

 

Standard Normal Distribution

The Standard Normal Distribution is a normal distribution with a mean m = 0 and a standard deviation s = 1. The observation values in a standard normal distribution are denoted by the letter Z.


Related Discussions:- Normal distribution

Finding the area of a triangle, Q. Finding the Area of a Triangle? Ther...

Q. Finding the Area of a Triangle? There are three commonly used methods to find the area of a triangle. The method you use to find the area depends on the information you kno

Calculus Homework, Find the slope of the line tangent to the graph of f(x)=...

Find the slope of the line tangent to the graph of f(x)= 3-2ln(2x^2+4) at the point (4, F(4))

Word problems, if I read 6 hours of spring break how many minutes did ...

if I read 6 hours of spring break how many minutes did read

Weighted mean-progression, Weighted mean - It is the mean which employ...

Weighted mean - It is the mean which employs arbitrarily given weights - This is a useful measure especially whereas assessment is being done yet the situation prevailing a

Calculus, Given f (x) =10x^3 - x^5 , find all intervals(in Interval Notatio...

Given f (x) =10x^3 - x^5 , find all intervals(in Interval Notation) of Concavity and the x-values of all Inflection Points.

Case let, How should Shoppers’ Stop develop its demand forecasts?

How should Shoppers’ Stop develop its demand forecasts?

Union of sets, Union of Sets Venn diagram presenting the union of sets...

Union of Sets Venn diagram presenting the union of sets A and B or A?B = Shaded area is demonstrated below: A ?B = Shaded area

Give an example of numerator and denominator, Give an example of Numerator ...

Give an example of Numerator and Denominator? Fractions represent parts of a whole object. Fractions are written using a horizontal line, with one number on top of the line and

Circles - common polar coordinate graphs, Circles - Common Polar Coordinate...

Circles - Common Polar Coordinate Graphs Let us come across at the equations of circles in polar coordinates. 1. r = a . This equation is saying that there is no matter

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd