19 8 pts Salaries of 11 college graduates who took a statistics course in college have a mean of $75,244 and a standard deviation of $1,185. Assume that prior studies have shown that the standard deviation of salaries of college graduates who have taken a statistics course in college is $2000. Construct a 98% confidence interval for estimating the population mean. Enter the lower bound of the confidence interval. (Round your answer to nearest whole dollar.) Question 20 7 pts John wishes to estimate the population mean salary of college graduates who took a statistics course in college. How many college graduates must he survey? Assume that the population standard deviation is known to be $1,563, and he wants to be 98% confident that the sample mean is within $121 of the true population mean