The employees of a large international company would like to have vision care as part of their benefits package. A researcher needs to estimate the amount of money that employees and their beneficiaries spend on such treatment, on average. A sample of 1024 employees reveals the mean amount spent last year was $583.67, with a standard deviation of $110.70. We assume that the population standard deviation is close to the last number.

The employees of a large international company would like to have vision care as part of their benefits package. A researcher needs to estimate the amount of money that employees and their beneficiaries spend on such treatment, on average. A sample of 1024 employees reveals the mean amount spent last year was $583.67, with a standard deviation of $110.70. We assume that the population standard deviation is close to the last number. (a) Construct a 90% confidence interval for the population mean amount spent on vision care. 2 Round the confidence interval values to 2 decimal places. What is the 90% confidence interval? (b) Construct a 99% confidence interval for the population mean amount spent on vision care. 2 Round the confidence interval values to 2 decimal places. What is the 99% confidence interval? (c) What is not true about the confidence intervals? (\"g There is no relation between length of the confidence interval and the confidence level. '_\