How much area is in both tails (combined)? (Enter an exact number as an integer, fraction, or decimal.)

Question

The mean age for all Foothill College students for a recent Fall term was 33.2. The population standard deviation has been pretty consistent at 15. Suppose that twenty-five Winter students were randomly selected. The mean age for the sample was 30.4. We are interested in the true mean age for Winter Foothill College students. Let X = the age of a Winter Foothill College student.

Construct a 95% Confidence Interval for the true mean age of Winter Foothill College students by working out then answering the exercise.

How much area is in both tails (combined)? (Enter an exact number as an integer, fraction, or decimal.)

α = 

Answer 1

the error margin is 1.96 * 15/sqrt(25) = 1.96*15/5 = 1.96*3 = 5.88

(30.4 - 5.88, 30.4+5.88)

(24.52, 36.28)