(a)Construct a 90% confidence interval for the mean increase in breathing rate due to exercise. Let d represent the breathing rate after exercise minus the breathing rate at rest. Use the TI-84 Plus calculator and round the answers to one decimal place.

Breathe deeply: Breathing rates, in breaths per minute, were measured for a group of ten subjects at rest, and then during moderate exercise. The results were as follows: Subject Rest Exercise 1 19 35 2 17 31 3 17 37 4 21 38 5 20 39 6 21 33 7 15 36 8 15 34 9 14 30 10 21 33