Your twenty observations of Dr. Knowitall reveal the following information. Assume that the estimate is to be within 8 percent of the true proportion 99 percent of the time.

Activity Observed	Number of Times Observed
With patient	4
Reviewing test results	4
On phone	6
Idle	4
Away on emergency	2
Not available	3
Total	23

(a)

Calculate the sample size needed to estimate the proportion of time Dr. Knowitall spends away on emergencies.

(Round your answer to the whole number, the tolerance is +/-1.)

Sample size needed is enter a sample size .