Ch. 11 Q 10 As part of the Women\'s Health Trial, one grou pof women were encour
ID: 3384856 • Letter: C
Question
Ch. 11 Q 10
As part of the Women's Health Trial, one grou pof women were encouraged to adopt a low-fat diet while a second group received no dietary counseling. A year later, the women in the intervention group had successfully maintained their diets. At that time, a study was undertaken to determine whether their husbands also had a reduced level of fat intake.
B) Formally test the null hypothesis that the two groups of men have the same mean dietary fat intake using a two-sided test. What do you conclude?
C) Construct a 95% Confidence Inerval for the true difference in population means.
Explanation / Answer
H0: mu1 =mu2
Ha: mu1 not equal to mu2
The mean of Group One minus Group Two equals -14.700
standard error of difference = 44.436
t = 0.3308
df = 302
95% confidence interval of this difference: From -102.144 to 72.744
The two-tailed P value equals 0.7410
By conventional criteria, this difference is considered to be not statistically significant.
Hence accept null hypothesis that two means are equal.
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D)
The mean of Group One minus Group Two equals -13.000
95% confidence interval of this difference: From -204.865 to 178.865
t = 0.1333
df = 302
standard error of difference = 97.500
The two-tailed P value equals 0.8940
By conventional criteria, this difference is considered to be not statistically significant.
Hence accept null hypothesis.
Group Group One Group Two Mean 54.800 69.500 SD 350.969 422.144 SEM 28.100 34.700 N 156 148