a statistics professor has 115 students in a statistics class and would like to estimate the number of hours each student studied for the last exam. a random sample of 41 students was found to study an average of 7.3 hours with a standard deviation of 1.9 hours. the 98% confidence interval to estimate the average number of hours studying for the exam would be..
a- 5.18 and 9.42
b- 6.72 and 7.88
c- 5.82 and 8.79
d- 6.11 and 8.49
