10

1. Many clinics offer weight-reduction programs. To test the effectiveness of one of these programs, ten people were weighed before starting the program and after following the program for one month. Data are presented below. (By the way, I am not real sure whether the program will lower or raise weight, but assume that the underlying population is normally distributed.)

Weight

Person Before After

1 132 125

2 231 220

3 128 109

4 165 172

5 133 130

6 149 140

7 260 271

8 141 134

9 188 180

10 193 179

All t-tests have two things in common: a numerator and a denominator. What are these two terms in the t-tests?

		An effect size divided by its standard deviation
		The difference between 2 standard deviations divided by a mean term
		The difference between 2 means divided by the standard error of estimate
		The difference between 2 means divided by a standard deviation (error) term