11-41.
Azerlieve Zynumbic
nA=24 nZ=32
sA = 37.5 seconds sZ = 41.3 seconds
Ho:OA=Oz;HA:OA# Oz
F = (SA2/Sz2) = (37.5)2/ (41.3)2 = 0.824
DA=24-1=23;Dz=32-1=31;a=0.05
The Rejection Region from the table is R = {F: F < 0.448 or F > 2.132}
F = 0.448 < F = 0.824 < Fu = 2.132 so we fail to reject the null hypothesis
The data does not provide sufficient evidence that a difference in the variability of the time until pain relief occurs between the two drugs exists.
11-44.
Ho: 01 = 02; HA: 01 # 2
F = S 2 / S2 = 20502 / 20842 = 0.9676
D=75 -1 =74; D=205 -1=204; a=0.10
Critical Value: F* = 1.267
F = 0.9676 < F* = 1.267; Fail to reject the null hypothesis
There is not sufficient evidence that there is any difference between the variability of student loans for the two universities.
11-45.
Ho: 0c = Oo; HA: 0c # 0o; a = 0.05; nc = 140; no = 75
Xc = 64.45; Xo = 61.96; Dc= 139; Do = 74; Sc = 7.9896; So = 7.6793
F1 = (7.9896)2 / (7.6793)2 = 1.0824; F1* = 1.414; Fail to reject the null hypothesis
F2 = (7.6793)2 / (7.9896)2 = 0.9238; F2* = 1.386; Fail to reject the null hypothesis.
There is not sufficient evidence to suggest a difference in the variability in speeds in the two types of vehicles exists.