Write the quadratic equation whose roots are −6 and 3, and whose leading coefficient is 4. (Use the letter x to represent the variable.)

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