# Tips And Tricks And Shortcuts For Elementary Statistics

## Shortcuts For Questions of Elementary Statistics

Statistics is an important topic for the recruitment exams. Although the topic is lengthy and the calculations are time taking. Therefore, Tips And Tricks For Elementary Statistics are really important. These questions are totally data based and require attention and knowledge of formulas as the questions are generally formula based but with good amount of calculations.

The image below consists of Tips And Tricks and formulas For Elementary Statistics that are specifically used in solving Statistics problems.Before attempting the problems going through these formulas will make your task easier and it will help you in solving most of the questions based on elementary statistics.

### Tips 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:

As we know through the given formulas, 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

In order to find Median we’ll arrange the numbers in ascending order first.

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

Since,the middle term of the series (in which number of observations is odd) 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=$\sqrt{4} =2$

You can also solve more questions on elementary statistics to improve your command on this topic.