Of 43 bank customers depositing a check, 18 received some cash back. (a) Construct a 90 percent confidence interval for the proportion of all depositors who ask for cash back. (b) Check the normality...

Of 43 bank customers depositing a check, 18 received some cash back. (a) Construct a 90 percent confidence interval for the proportion of all depositors who ask for cash back. (b) Check the normality assumption.

In a grocery parking lot 32 of 136 cars selected at random were white. (a) Construct a 99 percent confidence interval for the true proportion of white cars. (b) May normality be assumed? Explain.