Question

What is the standard deviation of the following data set rounded to the nearest tenth? 56,78,123,34,67,91,20

Answer 1

Answer:

32.2

Step-by-step explanation:

The given data set is:

56,78,123,34,67,91,20

The mean of this data set is

$\frac{56+78+123+34+67+91+20}{7} =\frac{469}{7} =67$

The standard deviation is given by;

$SD=\sqrt{\frac{\sum(x-\bar X)^2}{n} }$

$SD=\sqrt{\frac{(56-67)^2+(78-67)^2+(123-67)^2+(34-67)^2+(67-67)^2+(91-67)^2+(20-67)^2}{7} }$

$SD=\sqrt{\frac{7252}{7} }$

$SD=\sqrt{1036}=32.2$