Research psychologists measured the baseline breathing patterns-the total ventilation (in liters of air per minute) adjusted for body size-for each of n = 30 patients, so that they could estimate the average total ventilation for patients before any experimentation was done. The data, along with some MINITAB output, are presented here:

Stem-and-Leaf Display: Ltrs/min
Stem-and-leaf of Ltrs/min N = 30
Leaf Unit = 0.10

Descriptive Statistics: Ltrs/min

a. What information does the stem and leaf plot give you about the data? Why is this important?
b. Use the output to construct a 99% confidence interval for the average total ventilation for patients.

5.23 5.72 5.774.99 5.12 482 5.54 4.79 5.16 5.84 455.14 5.32 496 563 5.92 6.04 5.83 5.32 6.195.70 4.72 5.38 5.48 5.37 4.96 5.58 4.67 517 6.34 6.58 4.35 5.63 3 7913579 79135781 356812468035 444455555666 125824417421 1(11 Variable N N*e SE Mean StDev Ltrs/min 30 0.0997 0.5462 03 Maximum 6.5800 0 5.3953 Minimum 01 Median 4.3500 4.9825 5.3750 5.7850