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

Marginal probability, Marginal Probability Probability of event A happe...

Marginal Probability Probability of event A happening, denoted by P(A), is called single probability, marginal or unconditional probability. Marginal or Uncondi

Homomorphism, Let G be a group acting on a set X. The action is called fait...

Let G be a group acting on a set X. The action is called faithful if for any g ≠ 1 ∈ G there exists an x ∈ X such that gx ≠ x. That is, only the identity fi xes everything. Prov

What is universal set, A non-empty set or group of which all the sets under...

A non-empty set or group of which all the sets under concern are subsets is known as the universal set. In any part of application of set theory, all the sets under concern might l

Unit circle, Unit circle A circle centered at the origin with radius 1 ...

Unit circle A circle centered at the origin with radius 1 (i.e. this circle) is called as unit circle.  The unit circle is very useful in Trigonometry. (b) x 2 + ( y - 3) 2

Mechanics, find the composition of the simple harmonic motion of the same p...

find the composition of the simple harmonic motion of the same period in the perpendicular directions

What is the length of one side of the square, The area of a square is 64 cm...

The area of a square is 64 cm 2 . What is the length of one side of the square? To find out the area of a square, you multiply the length of a side through itself, because all

Definition of a function, A function is a relation for which each of the va...

A function is a relation for which each of the value from the set the first components of the ordered pairs is related with exactly one value from the set of second components of t

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