PSYC 354 Quiz 8 The One-Sample t-Test

PSYC 354 Quiz 8: The One-Sample t-Test

1. As sample size increases, the distribution of t statistics becomes flatter and more spread out.
2. Two samples are selected from a population, and a treatment is administered to the samples. If both samples have the same mean and the same variance, a researcher is more likely to reject the null hypothesis and find a significant treatment effect with a sample of n = 100 than with a sample of n = 4.
3. If other factors are held constant, the larger the sample size is, the greater the likelihood of rejecting the null hypothesis.
4. A random sample with n = 20 scores has df = 19.
5. If a treatment is expected to decrease scores in a population with μ= 30, then the alternative hypothesis is μ ≤ 30.
6. If a researcher is using a t statistic to test a null hypothesis about a population, what information is needed from the population to calculate the t statistic?
7. All else constant, which of the following would not have an effect on the width of a confidence interval?
8. If other factors are held constant, the larger the value of the sample variance, the lesser the likelihood of rejecting the null hypothesis.
9. For a hypothesis test with alpha level held constant, as sample size increases the critical values obtained from the t distribution increasingly resemble the critical values obtained from the z
10. What is the sample variance and estimated standard error for a sample of n = 9 scores with SS = 72?
11. A sample of n = 25 scores has a mean of M = 40 and a standard deviation of s = 10. What is the estimated standard error for the sample mean?
12. It is expected that a treatment will reduce scores on a variable. If α
    = .05, what is the critical t value for a one-tailed hypothesis test with n = 15?
13. The null hypothesis for a research study states that μ = 70. If a researcher obtains a sample with M = 73 and s2 = 9, then Cohen’s d = 0.33.
14. The results of a hypothesis test are reported as follows in a scientific report: t(15) = 2.70, p < .05. Based on this report, how many individuals were in the sample?
15. A researcher conducts a hypothesis test using a sample from an unknown population. If df = 30 for the t-statistic and M = 46 and s2
    = 10, how many individuals were in the sample?