Chapter 12.2, Problem 10CYU

a)

To determine

To find : Given data is sample or population.

Answer to Problem 10CYU

A population.

Explanation of Solution

Given Information :

A table shows maximum speed limits in mph for interstate highways in question.

A population.

Since, it is for all state across interstate.

b)

To determine

To find : Standard deviation of the speeds.

Answer to Problem 10CYU

  $4.34$

Explanation of Solution

Given Information :

A table with data is shown in question.

Formula Used:

  $\sigma =\sqrt{\frac{{\displaystyle \sum _{k=1}^h{(x_k-\mu )}^2}}{n}}$

Calculation :

  $\sigma =\sqrt{\frac{941.78}{50}}=4.34$

Standard deviation is $\mathrm{4.34.}$