Question

A researcher wishes to determine whether smoking cigarettes has a positive or negative impact on an individual’s weight. They find 6 sets of twins, in which one twin is a non-smoker (X), while the other is a cigarette smoker (Y). The data for these individuals is represented below (in lbs.):

X:180 140 165 200 175 110

Y: 205 135 195 220 200 105

What is the null hypothesis? A) H0: ?? = 0 B) H0: ?? = 0 C) H0: ?? − ?? = 0 D) H0: ?̅> 0

What is ?̅equal to? A) 5 B) 20 C) 0 D) -15 E) -25

What is t-score for this hypothesis? Hint: Calculate sd using Excel or by hand. A) -2.32 B) -0.84 C) 1.12 D) -2.88

Suppose α = 0.10. What do we conclude about this hypothesis test? A) Fail to reject null hypothesis. B) Accept the null hypothesis. C) Reject the null hypothesis, there is evidence to conclude that smokers have a higher average body weight. D) Reject the null hypothesis, there is evidence to conclude that that non-smokers have a higher average body weight.

If a null hypothesis is rejected against an alternative at the 5% level, then using the same data, it must be rejected against that alternative at the 1% level. A) True B) False

Answer 1

a)

null Hypothesis:

μd

=

0

  ?̅equal =-15

t-score =-2.32

C) Reject the null hypothesis, there is evidence to conclude that smokers have a higher average body weight.

B) False