During the painting of cars at a car factory, a mistake can occur which later leads to bubble formations in the paint. One examines the varnish on 32 cars and of these have 5 the error. The factory manager wants a 90% confidence interval for the proportion of cars with the fault.

a) Estimate the error rate. 0.156 Round your answer to 3 decimal places. Your answer is correct The answer is correct. You achieved 1 point. You received 1 point for this task. Score: 1/1Your answer is correct Answered.

b) The interval must have a margin of error of 3% . How many cars must be examined for this to be achieved? The number must be valid regardless of how large or small the percentage of errors is. Round your answer to the nearest whole number. Your answer is incorrect This feedback is based on your last submitted answer. Submit your changed answer to get updated feedback. The answer is wrong. You received 0 points for this assignment. Score: 0/1Your answer is wrong Answered. c)

The interval must have a margin of error of 3% . How many cars must be examined for this to be achieved? Assume that the error rate you estimated is the correct value. Round your answer to the nearest whole number.

ive managed to do task a) but im really stuck on task b and c.