TESTING THE MEANS OF TWO POPULATIONS
DEPENDENT SAMPLES
FORMULA:
With n-1 degrees of freedom
Where:
Sample problems:
1. A study was conducted to investigate some effects of physical training.
At 0.05 level of significance, test the claim that the mean pre-training
weight equals the mean post-training weight. The weights are in
kilograms. What do you conclude about the effect of training weight?
Pre-training weight :
99 57 62 69 74 77 59 92 70 85
Post-training weight :
94 57 62 69 66 76 58 88 70 84
2. A dose of the drug Captropil, designed to lower systolic blood
pressure, is administered to 10 randomly selected volunteers, with
the following results. Test the effectiveness of the drug.
Systolic blood pressure before pill :
120 136 160 98 115 110 180 190 138 128
Systolic blood pressure after pill:
118 122 143 105 98 98 180 175 105 112
