Evaluate the given integral by making an appropriate change of variables. 10 x ? 5y 8x ? y da, r where r is the parallelogram enclosed by the lines x ? 5y = 0, x ? 5y = 2, 8x ? y = 5, and 8x ? y = 10

Arandom sample of 45 observations results in a sample mean of 68. the population standard deviation is known to be 23 a. compute the margin of error at a 959% confidence interval. b. compute the 95% confidence interval for the population mean c. compute the 90% confidence interval for the population mean. d. compute the 75% confidence interval for the population mean