Chapter 8.5, Problem 13E

To determine

To calculate the $95\%$ confidence interval for the mean weight.

Answer to Problem 13E

From the above MINITAB output, the $95\%$ confidence interval for the mean weight of NFL football players in $2010\text{ is }\left(235.39,261.38\right)$.

Explanation of Solution

Given information:

n = 52,

$\overline{x}=248.38$

$s=46.68$.

$\begin{array}{l}305265287285290235300230195\hfill \\ 236244194190307218315265210\hfill \\ 194216255300315190185183313\hfill \\ 246212201308270241242306237\hfill \\ 315215200295187204257185255\hfill \\ 318230316200324245185\hfill \end{array}$

Calculation:

MINITAB procedure:

Step $1:$ Choose Stat $>$ Basic Statistics $>1-$ Sample $t$.

Step $2:$ In Samples in Column, enter the column of Football players.

Step $3:$ Check Options, enter Confidence level as $90.0$.

Step $4:$ Choose not equal in alternative

Step $5:$ Click OK in all dialogue boxes.

MINITAB output:

One-Sample T: Football players

$\begin{array}{l}\text{Variable N Mean StDev SE Mean 95\%}\text{CI}\\ \text{Football players 52 }\text{248}\text{.38}46.686.47\left(235.39,261.38\right)\end{array}$

From the above MINITAB output, the $95\%$ confidence interval for the mean weight of NFL football players in $2010$ is $\left(235.39,261.38\right)$.