According to a Department of Education survey 33 of college

According to a Department of Education survey, 33% of college students say they experience stress in their daily lives. Consider the proportion .33 from the Department of Education survey as the true population proportion. In a class of 45 students, what is the probability that the proportion p of students who experience stress is greater than .365?

A. .3085

B. .6915

C. .1808

D. .1915

E. .3192

Solution

The standard error of the proportion is

sp = sqrt[p(1 - p) / n]

Thus,

sp = 0.070095

Thus, using Excel, we type on any empty cell

=1 - NORMDIST(0.365, 0.33, 0.070095, 1)

= 0.3088 or option A, 0.3085 due to some rounding off.

Again, it is OPTION A. [ANSWER]