Tips And Tricks And Shortcuts For Elementary Statistics

Tips And Tricks And Shortcuts For Elementary Statistics Questions

Here are few tips and tricks to solve Elementary Statistics questions.These questions are totally data based and requires attention and knowledge of formulae as questions are formula based.This page is specifically to provide tips and tricks to solve the problems easily.

Tips and Tricks For Elementary Statistics

The image below consists of key formulae used in solving Elementary Statistics problems.Before attempting the problems go through these formulae, it will help you in solving most of the questions of Elementary Statistics.

Tips,Tricks and Shortcuts to Solve Elementary Statistics:

Type 1: Find the Mean,Median and Mode of the following set of data.

2,5,3,4,2,7,9,2,3

Solution:

Mean = \frac {\text{sum of all the elements}}{\text{number of elements}}

= \frac{2+5+3+4+2+7+9+2+3}{9}

= \frac{37}{9}

=4.111

Median=Arrange the numbers in ascending order

=2,2,2,3,3,4,5,7,9

Since,the middle term of the series is the median

Hence,3 is the median of the above series

Now,Mode=The most frequent value in the set

In the above set we can see 2 is the most number of repeated value

Hence,the mode is 2.

Type 2: Consider the following set of data and find the variance and the standard deviation.
2,4,4,4,5,5,7,9
Solution:

Mean of these numbers= \frac{2+4+4+4+5+5+7+9}{8}

= \frac{40}{8}

=5

Variance =\sigma ^{2} =\frac{\sum(x_{i}-\bar{x})^{2}}{N-1}

(2-5)^{2}=-3^{2}=9 (4-5)^{2}=-1^{2}=1 (4-5)^{2}=-1^{2}=1 (4-5)^{2}=-1^{2}=1 (5-5)^{2}=0^{2}=0 (5-5)^{2}=0^{2}=0 (7-5)^{2}=2^{2}=4 (9-5)^{2}=4^{2}=16

 

Variance=\frac{9+1+1+1+0+0+4+16}{8}

 

Variance=\frac{32}{8}

variance=4

and,Standard deviation= \sqrt{4} =2