Chapter 8.3, Problem 82E

To determine

To find: The t-critical value at 98% confidence level.

Answer to Problem 82E

The critical value is 2.508

Explanation of Solution

Given:

Confidence level = 98%

Sample size ( n ) = 23

Calculation:

Level of significance $\left(\alpha \right)=1-0.98=0.02$

Since, sample standard deviation is known t -critical value is to be calculated.

Degree of freedom can be calculated as:

  $\begin{array}{c}df=n-1\\ =23-1\\ =22\end{array}$

The critical value at 2% level of significance can be calculated as:

  $\begin{array}{c}{t}_{\alpha /2,df}=t_{0.02/2,22}\\ =2.508\end{array}$

Thus, the critical value is 2.508.

Hence, the correct option is (e).