2698 2628 2474 2895 2672 2675 2486 2852 2733 2655 2765 2794 2486 2627 2624 2785 2692 2654 2518 2650
a. Draw normal probability plot for the above data and make comment.
b. Assuming given data to be approximately normally distributed, Construct 90%, 95% and 99% confidence intervals for the mean number of hours that the LED lights of this brand has worked.
c. Construct 90%, 95% and 99% confidence intervals for the standard deviation of the number of hours that the LED lights of this brand worked.
