Question 4 (2 points) If 70 workers were divided in to two groups of 30 and 40 workers. It was found that the group of the 30 workers finished the work in an average time of 15 minutes with a standard deviation of 4 minutes, while the group of the 40 workers finished the work in an average time 23 minutes with a standard deviation of 10 minutes. Find a 99% confidence interval for the difference in the mean finishing times for these two groups. 0 (-12.49,-3.15) Q (-12.49,3.15) Q (-3.15,-12.49) Q (3.15,12.49)