Q. 3.125 - Elementary Statistics

Question

The data set has size $80$. Approximately how many observations lie within two standard deviations to either side of the mean? 

Step-by-Step Solution

Answer

The observations that  lie within two standard deviations to either side of the mean approximately are $76$

Step 1 : Given information

We are given that data set has size $80$

Step 2: Explanation

Here we  will use Empirical Rule , for normally distributed random variable, $95\%$of the measures are within two standard deviation of the mean.

We are given the size of data set to be$80$  , as here distributions are normal ,

So we get ,$0.95\times 80=76$

Approximately,$76$ observation lie within two standard deviations of the mean