A professor wants to estimate how long students stay connected during twohour online lectures. From a random sample of 24 students, the mean stay time was 81 minutes with a standard deviation of 15 minutes. Assuming the population has a normal distribution, develop a 98% confidence interval estimate for the population mean by determining the following values: 1. a) Point Estimate = C] b) df = C] Significance level (a) = C] c) Determine the critical value rounded to 3 decimal places. Enter a positive value. [3 decimal places] Critical value=CJ d) [3 decimal places] Standard Error=:] e) [1 decimal place] Margin of Error=CJ f) [1 decimal place] Lower Confidence Limit=C] g) [1 decimal place] Upper Confidence Limit=Cj 2. Should we reject a claim that the population mean, u = 70 minutes? Why? Select an answer a 3. If the confidence level decreases, what will be the effect on the margin of error? Select an answer a