Task#1: Human Resource Consulting (HRC) surveyed a random sample of 60 construction companies to find information on the costs os their health care plans. One of the items being tracked is the annual deductible that employees must pay. The Minnesota Department of Labor reports that historically the mean deductible amount per employee is $502 with a standard deviation of $100.
1) Compute the standard error of the sample mean for HRC.
2) What is the chance HRC finds a sample mean between $477 and $527?
3) Calculate the likelihood that the sample mean is between $492 and $512.
4) What is the probability that the sample mean is greater than $550?
1) You plan to conduct a survey to find out what proportion of the workforce has two or more jobs. You decide on the 95% confidence interval and a margin of error of 2%. A pilot survey reveals that 5 of the 50 sampled hold two or more jobs. How many in the workforce should be interviewed to meet your requirements?
2) As part of the annual review of its accounts, a discount brokerage selected a random sample of 36 customers and reviewed the value of their accounts. The mean was $32,000 with a sample standard deviation of $8,200. What is a 90% confidence interval for the mean account value of the population of customers?