Answer
97.9455 to 98.4605
Work Step by Step
Mean = $\frac{98.74+98.83+...+98.92+98.33}{20}$ = 98.203
x - $z_{a/2}$ $\times$ $\frac{o}{\sqrt n}$ to x + $z_{a/2}$p $\times$ $\frac{o}{\sqrt n}$
98.203 - 1.645 $\times$ $\frac{.7}{\sqrt 20}$ to 98.203 + 1.645 $\times$ $\frac{.7}{\sqrt 20}$
