10-16 (modified) The mechanical engineer who designed the physical therapy device discussed in the example collected the following data for the amount of time (hours) spent by the test patients using his machine: 8 12 26 10 23 21 16 22 18 17 36 9 Construct a 99% confidence interval estimate for the mean time spent until recovery by all back patients who use the same therapy. Lower Confidence Bound= Upper Confidence Bound=