Math 10Homework 5 ANSWERSAdditional Problems:1.The average number of years of post secondary education of employees in an industry is 1.5. A company claimsthat thisaverageis higher for its employees. A random sample of 16 of its employees has anmeanof 2.1 yearsof post secondary education with astandard deviationof 0.6 years.a.Find a 95% confidence interval for the mean number years of post secondary education for thecompany’s employees. How does this compare with the industry value?
2.When polling companies report a margin of error, they are referring to a 95% confidence interval. Go to thewebsite and verify the stated margins of error for 2 polls.Many answers possibleConstructing Confidence IntervalsIn Exercises 3 and4 you are given the sample mean and the sample standarddeviation. Assume the random variable is normally distributed and use a t distribution to construct a 95%confidence interval for the population mean.What is the margin of error of the confidence interval?3.Repair Costs: MicrowavesIn a random sample of five microwave ovens, the mean repair cost was $75.00 andthe standard deviation was $22.214.171.124$,50.59$5.15755/)50.12(776.275(t with 4 df)4.Repair Costs: ComputersIn a random sample of seven computers, the mean repair cost was $100.00 and thestandard deviation was $126.96.36.199$,70.60$3.391007/)50.42(447.2100(t with 6 df)5.You did some research on repair costs of microwave ovens and found that the standard deviation is=$15.Repeat Exercise 3, using anormal distributionwith the appropriate calculations for a standard deviation that isknown. Compare the results.