No Spacing Heading 1 Heading 2 Title Styles Dictate Sensitivity Pane A researcher wants to estimate the mean number of hours spent on required athletic activities by all student-athletes in the conference. How large of a sample should be selected if the researcher wants to be 95% confident that the sample mean is within 0.5 hour of the population mean? From past data the standard deviation is o = 2.3. a. 9 b. 30 C. 58 d. 82