A new stock broker in a city, has offered free initial consultations to new clients. The stock broker wants to estimate the proportion of new clients that return after the free initial consultation. Of the 75 randomly sampled new clients, 60 returned. In this question, use a MINIMUM OF 4 DECIMAL PLACES in all your calculations.

SHOW BRIEF WORKINGS TO SUPPORT YOUR ANSWER.

a) What is the value of the sample proportion of clients who return? Please give your value to 4 decimal places.

b) Check conditions for proportions.

c) Construct and interpret a 90% confidence interval for the population proportion.