5) Determine the point estimate of the population mean and margin of error for the condence interval with lower bound 7 and upper bound: 25. 6) The grade point averages for 10 randomly selected junior college students are listed below. Assume the grade point averages are normally distributed. Find a 98% confidence interval for the true mean. Round to the nearest hundredth. 2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 0.8 7) The principal at Riverside High School would like to estimate the mean length of time each day that it takes all the buses to arrive and unload the students. How large a sample is needed if the principal would like to assert with 90% condence that the sample mean is off by, at most, 7 minutes. Assume that s = 14 minutes based on previous studies