Use the following data table comparing a control group to a group balloons implanted in leg arteries:

Variables control group balloons group   (n = 54)  (n = 48) Baseline Rutherford stage 3.1  0.8 3.4  0.8 Degree of stenosis 91  7 89  8 Target lesion length (cm) 7.4  6.7 7.5  6.2 Target lesion diameter (cm) 4.7  0.6 5.0  0.7 No. of runoff vesicles 2.1  0.8 1.8  0.8 

1. Perform hypothesis tests on all five variables ( comparing one group to the other). State the null hypothesis for each. List the p-value and a specific conclusion.
2. Calculate by hand the Satterthwaite's degrees of freedom for target lesion diameter (the fourth variable). Show your steps. Your answer should be the exact number that would be used in a table to look up the p-value in the subsequent hypothesis test.
3. Construct a 99% confidence interval for degree of stenosis, balloons group

Please show work/relevant equations.