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In order to estimate the average number of hours per day that children ages 12 to 15 from XYZ Junior High School spend in front of a screen, the following information was obtained from a random sample of school kids in that age group n = 25 I = 6.6 8 = 2.5 Based on these sample survey results, answer the following questions - a. Assume that the distribution of screen times for all school kids in this age group is normally distributed. If the desired confidence level is 95 %, which of the following is the appropriate critical value? O 1= 1.711 O z = 1.96 O z = 1.645 O t=2.064 b. Which of the following is the point estimate for the true population mean (#)? O 6.6 6.6 - 1.032 6.6 + 1.032 O 6.6-2.5 c. Which of the following is the approximate value of the upper limit of a 95 % confidence interval for the population mean (14)? 7.632 5.568 4.568 O 8.632 d. If you are testing the null hypothesis Ho : p = 5.4, which of the following would be your test statistic value? O 24 O 0.48 O 0.48 O -24