Question

A university planner wants to determine the proportion of spring semester students who will attend summer school. She surveys 360 current students and finds that that 120 will return for summer school. The 99% confidence interval for the proportion of students who attend summer school is:

Answer 1

The 99% confidence interval for the proportion of students who attend summer school is (0.306, 0.44)

Step-by-step explanation:

Let the proportion of students who will return be:

p = 120/320 = 0.375

q = 1 - p = 1 - 0.375 = 0.625

The sample size, n = 32 0

The Z value for a 99% confidence interval is: 2.576

The confidence intervale is given by:

0.375 ± 2.576 * √(0.375*0.625)/320

0.375 ± 2.576 * 0.027

0.375 ± 0.069

UPPER limit 0.44

LOWER limit 0.306