X Incorrect. A random sample of 25 life insurance policyholders showed that the average premium they pay on their life insurance policies is $ 631 per year with a standard deviation of $90. Assuming that the life insurance policy premiums for all life insurance policyholders have a normal distribution, make a 99% confidence interval for the population mean, w. Round your answers to cents. 677.37 to $ 584.63 Attempts: 2 of 2 used