Chapter 11, Problem 5STP

To determine

To Calculate : Standard deviation for the given data.

Answer to Problem 5STP

  $7.8248$

Explanation of Solution

Given information :

We know that, data related to grades earned by students is given.

Formula Used:

  $\sigma =\sqrt{\mathrm{var}x};\mathrm{var}x=\frac{1}{n}\Sigma {(x_i-\overline{x})}^2$

Calculation :

  $\begin{array}{l}\overline{x}=\frac{\Sigma x_i}{n}=83.85\\ \therefore \mathrm{var}x=\frac{1}{20}\times 1224.55=61.2275\\ \therefore \sigma =\sqrt{61.2275}=7.8248\end{array}$