prb a SAT math scores of a random sample of 1000 high school

(a) SAT math scores of a random sample of 1000 high school seniors in the state of Florida are collected, and the sample mean score and the standard deviation are found to be 505 and 115, respectively. Find a confidence interval for the true mean SAT math score for the U.S. high school senior using 99% confidence level. (b) How many high school seniors should we sample if we want to estimate the true mean SAT math score with an error of 15 points under the condition that we use 95% confidence level and the true standard deviation is 110?

Solution

You have done very good work here.

It is correct also.

Just note that , sample size can\'t be fraction.

Therefore, approximate value for 14.37 is 15

15 high school seniors should we sample.