Stats chapter 9
Which of the following summarizes a t test that was significant and associated with a large effect size?
t(12) = 2.95, p < .05, d = .82
Which measure of effect size is most commonly reported with a t test?
Cohen's d
A researcher conducts two t tests. Test 1 is a one-tailed test with a smaller sample size at a .05 level of significance. Test 2 is a one-tailed test with a larger sample size at a .05 level of significance. What do you know about the critical values for each test?
Test 2 is associated with smaller critical values
A key difference between a t statistic and a z statistic is that the standard error is ______ to compute a t statistic.
estimated
A researcher records the number of distracters (such as noises) that preschool-aged children ignore while watching a popular Sunday morning cartoon show. Assuming that the population variance is unknown, what type of t test is appropriate for this study?
one sample t test
You read about a study testing whether night shift workers sleep the recommended 8 hr/day. Assuming that the population variance of sleep (per day) is unknown, what type of t test is appropriate for this study?
one sample t test
State the critical value(s) for the following two-tailed t test at a .05 level of significance: t(∞).
±1.96 and the same as for a two-tailed z test at a .05 level of significance
The estimated standard error in the t statistic uses the ______ to estimate the ______ when the population variance is unknown.
sample variance; population variance
Two researchers (A and B) compute a one-sample ttest. For both tests, the mean difference between the sample and value stated in the null hypothesis is 5, but the standard error is smaller for Researcher A. Which test is more likely to result in a decision to reject the null hypothesis?
researcher A
The ______ is an inferential statistic used to determine the number of standard deviations in a t distribution that a sample mean deviates from the mean value or mean difference stated in the null hypothesis.
t-statistic
