How to find the 95% confidence interval for mean.
A small New England college has a total of 400 students. The Math SAT is mandatory for admission and the mean score of all 400 students is 620. The population standard deviation is found to be 60. The formula for a 95% confidence interval yields the interval 640 ± 5.88. Regulate whether each of the following statements is true or false.
a. The interval is incorrect. It is much too narrow.
b. If we repeated this procedure many, many times, X-bar would fall between 634.12 and 645.88 about 95% of the time