Both please

3. A customer service manager is reviewing the wait times experienced by customers on hold. They decide to conduct a study to measure the average wait time, accurate to within 3 minutes. If it is known from previous studies that the standard deviation in wait times is approximately 11.1 minutes, how many customers will need to be sampled to achieve the desired precision at the 95% confidence level? (2 marks) 4. You plan to conduct a survey to determine what proportion of the workforce has two or more jobs. You decide on a 90% level of confidence and state that the estimated proportion must be within 3% of the population proportion. (3 marks) a) A pilot study reveals 8 of the 50 sampled hold two or more jobs. How many in the workforce should be interviewed to meet your requirements? b) If there was no pilot study, how many in the workforce should be interviewed to meet your requirements