Q2) Independent-Samples
t-
Test
(Round calculated results to the hundredth (2
nd
place to the right of the decimal))
In a research project, researchers collected demographic and health data from a sample of elderly residents in the community. To examine any possible gender differences in their sample, they want to see if the females and the males differ significantly on the education level (number of years of formal schooling). The researchers are not predicting any direction in the possible gender differences so the hypotheses should be non-directional. They would like to run a two-tailed test with α = .10.
Male Subject ID
|
Education
|
|
Female Subject ID
|
Education
|
1
|
14
|
|
13
|
14
|
2
|
15
|
|
14
|
15
|
3
|
17
|
|
15
|
18
|
4
|
13
|
|
16
|
18
|
5
|
15
|
|
17
|
16
|
6
|
15
|
|
18
|
17
|
7
|
13
|
|
19
|
16
|
8
|
15
|
|
20
|
16
|
9
|
15
|
|
21
|
17
|
10
|
16
|
|
22
|
15
|
11
|
17
|
|
23
|
13
|
12
|
14
|
|
24
|
17
|
|
|
|
25
|
18
|
|
|
|
26
|
17
|
E. Calculate estimated variance for population 1 (s1^2) and estimated variance for population 2 (s2^2)
F. Calculate the pooled variance (S
pooled2
)from the two population variances (from question e above)
G. Use the pooled variance (from question f above) to calculate the variance for sampling distribution 1 (S
M12) and the variance for sampling distribution 2 (S
M22)
Hint: Sampling distribution is derived from the original population, and it consists of means of all possible samples drawn from the original population.
H. Calculate standard deviation (S
diffmean)of the comparison distribution
Hint: This comparison distribution consists of differences between all possible sample means drawn from the two sampling distributions. Its standard deviation is the denominator of the t statistic formula.