Exam 9: Introduction to the T Statistic

If a hypothesis test using a sample of n = 16 scores produces a t statistic of t = 2.15, then the correct decision is to reject the null hypothesis for a two-tailed test with $\alpha$ = .05.

A hypothesis test produces a t statistic of t = 2.20.If the researcher is using a two-tailed test with α = .05, how large does the sample have to be in order to reject the null hypothesis?

If the null hypothesis states that $\mu$ = 70 and a researcher obtains a sample with M = 73 and s² = 9, then Cohen's d = 0.33.

If the 90% confidence interval for µ is from 40 to 50, then the sample mean is M = 45.

If other factors are held constant, the bigger the sample is, the greater the likelihood of rejecting the null hypothesis.

If other factors are held constant, which set of sample characteristics is most likely to reject a null hypothesis stating that $\mu$ = 80?

A hypothesis test with a sample of n = 25 participants produces a t statistic of t = +2.53.Assuming a one-tailed test with the critical region in the right-hand tail, what is the correct decision?

A sample has a mean of M = 39.5 and a standard deviation of s = 4.3, and produces a t statistic of t = 2.14.For a two-tailed hypothesis test with α = .05, what is the correct statistical decision for this sample?

A sample of n = 16 scores with a sample variance of s² = 64 would have an estimated standard error of 4 points.

If other factors are held constant, as the sample variance increases, the estimated standard error also increases.

When the population variance or standard deviation is not known, you must use a t statistic instead of a z?score for a hypothesis test.

Which of the following is a fundamental difference between the t statistic and a z-score?

With α = .05, what is the critical t value for a one-tailed test with n = 15?

Two samples from same population probably will have different t statistics even if they are the same size and have the same mean.

For a hypothesis test using a t statistic, the boundaries for the critical region will change if the sample size is changed.

If two samples each have the same mean, the same number of scores, and are selected from the same population, then they will also have identical t statistics.

As the sample size is increased, the distribution of t statistics becomes flatter and more spread out.

Which set of characteristics will produce the smallest value for the estimated standard error?

A research report states "t(15) = 2.31, p < .05." For this study, the sample had n = 16 scores.

For a two-tailed hypothesis test with α = .05 and a sample of n = 25 scores, the boundaries for the critical region are t = ±2.060.