The sample standard deviation of the differences between the pretreatment and posttreatment KPS scores is 10.787. Using a 0.05 significance level, you need to test the claim that interventional bronchoscopic therapy improves functional impairment, i.e., that the KPS score is higher after the therapy.

Pretreatment (%) --> 90; 80; 90; 90; 90; 90; 80; 90; 50; 60; 50

Posttreatment (%) --> 100; 100; 100; 100; 100; 100; 100; 100; 80; 100; 80

If the null hypothesis is d 0, what is the alternative hypothesis?

a. x1 x2 0

b. x1 x2 > 0

c. d 0

d. d > 0

e. 1 2 0

f. 1 2 >0

What critical value(s) should you use to test the given hypothesis?

a. 1.812

b. 1.645

c. 2.228

d. -1.812

e. -1.645

f. -2.228

g. Both a and d

h. Both b and e

i. Both c and f