9 Of 45 bank customers depositing a check 21 received some c

9. Of 45 bank customers depositing a check, 21 received some cash back. (a) Construct a 90 percent confidence interval for the proportion of all depositors who ask for cash back. (Round your answers to 4 decimal places.) The 90% confidence interval is from to (b) May normality of p be assumed? No Yes

Solution

a)

Confidence Interval For Proportion
CI = p