A professor wants to estimate how long students stay connected during two-hour online lectures. From a random sample of 21 students, the mean stay time was 94 minutes with a standard deviation of 9 minutes. Assuming the population has a normal distribution, develop a 95% confidence interval estimate for the population mean by determining the following values: 1. a) Point Estimate = b ) df = Significance level (a) = c) Determine the critical value rounded to 3 decimal places. Enter a positive value. [3 decimal places] Critical value = d) [3 decimal places ] Standard Error = e) [1 decimal place ] Margin of Error = f) [1 decimal place] Lower Confidence Limit = g) [1 decimal place] Upper Confidence Limit = 2. Should we reject a claim that the population mean, u = 104 minutes? Why? Select an answer 3. If the sample size decreases, what will be the effect on the margin of error