Chapter 10, Problem T10.4SPT

To determine

To select the correct option for, which of the following statement is true.

Answer to Problem T10.4SPT

Option (a) is correct option.

Explanation of Solution

It is given in the question that Janelle uses a higher degrees of freedom than Tom.

And as we know that a higher degree of freedom results in a lower $t^{*}$ -value.

Thus, a lower $t^{*}$ -value results in a lower margin of error and thus also narrower confidence interval.

Thus, we know that Janelle’s confidence interval is narrower than Tom’s confidence interval or we can also say that the Tom’s confidence interval is wide than Janelle’s confidence interval.

Therefore, option (a) is correct option i.e. Tom’s confidence interval is wider.