Figures & data
Figure 1. The effect of the size and direction of the shift on skewness of the t-statistics when the parent population is for n = 20.
![Figure 1. The effect of the size and direction of the shift on skewness of the t-statistics when the parent population is for n = 20.](/cms/asset/1bdaa09e-1647-42ef-b481-f0740fc6e559/ujse_a_11910723_f0001_b.gif)
Figure 2. Power of the left- and right-tailed t-tests for shifts of 0.5σ under a
parent population for n=20 and α = 0.05.
![Figure 2. Power of the left- and right-tailed t-tests for shifts of 0.5σ under a parent population for n=20 and α = 0.05.](/cms/asset/05e8aceb-ab96-4e07-ab6a-74abc8d59e91/ujse_a_11910723_f0002_c.gif)
Figure 3. The power of the two-tailed t-test is not uniformly higher or lower for the parent than for the normal parent population for n = 20 and α = 0.05.
![Figure 3. The power of the two-tailed t-test is not uniformly higher or lower for the parent than for the normal parent population for n = 20 and α = 0.05.](/cms/asset/9f3101e6-3cbc-47a8-bf00-e7c98d964e0d/ujse_a_11910723_f0003_b.gif)
Table 1. Power of one-tailed t-test for various shifts and sample sizes under normal, , uniform, and contaminated normal (CN) parent populations, α = 0.05.
Table 2. Power of one-tailed t-test for various shifts and sample sizes under normal, , uniform, and contaminated normal (CN) parent populations, α = 0.10.
Figure 4 Power comparison for the two-tailed sign test versus the t-test when the parent population is for n=20 and α=0.0414.
![Figure 4 Power comparison for the two-tailed sign test versus the t-test when the parent population is for n=20 and α=0.0414.](/cms/asset/b310e754-0a08-4810-b62e-505ee5a5f26c/ujse_a_11910723_f0004_b.gif)
Figure 5 The power of the two-tailed sign test for low-, medium-, and high-kurtosis parent populations when n=20 and α = 0.0414.
![Figure 5 The power of the two-tailed sign test for low-, medium-, and high-kurtosis parent populations when n=20 and α = 0.0414.](/cms/asset/f89d0a24-0e84-41d5-98d1-0ecc5494f60b/ujse_a_11910723_f0005_b.gif)
Table 3. Power of one-tailed t and sign tests for normal and parent population.
Table 4. Power of one-tailed t and sign tests for low- (uniform), medium- (normal), and high-kurtosis (contaminated normal) parent populations.