Exam 9: Introduction to the t Statistic

A sample of n = 4 scores with SS = 48 has a variance of s² = 16 and an estimated standard error of 2.

If a sample of n = 16 scores is being used to make an 80% confidence interval estimate of the population mean,μ,what value(s)of t should be used?

Which combination of factors would definitely increase the width of a confidence interval?

If two samples are selected from the same population,under what circumstances will the two samples have exactly the same t statistic?

For a one-tailed test with α = .05 and a sample of n = 9,the critical value for the t statistic is t = 1.860.

Which of the following is not needed to compute a t statistic?

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

A sample of n = 25 scores produces a t statistic of t = 2.062.If the researcher is using a two-tailed test,which of the following is the correct statistical decision?

If other factors are held constant,as the sample size increases,the estimated standard error decreases.

A random sample with n = 20 scores has df = 19.

If two samples,each with n = 20 scores,are selected from the same population and both have the same mean (M = 53)and the same variance (s² = 12),then they will also have the same t statistic.

With α = .05 and df = 8,the critical values for a two-tailed t test are t = ±2.306.Assuming all other factors are held constant,if the df value were increased to df = 20,what would happen to the critical values for t?

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

With α = .01,the two-tailed critical region for a t test using a sample of n = 16 subjects would have boundaries of ______.

A sample with a mean of M = 40 and a variance of s² = 20 has an estimated standard error of 1 point.How many scores are in the sample?

Compared to a z-score,a hypothesis test with a t statistic requires less information from the population.

The t distribution for df = 4 is flatter and more spread out than the t distribution for df = 20.

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

Although hypothesis tests are affected by sample size,sample size has little or no influence on measures of effect size,such as r² or Cohen's d.

Which of the following describes what a confidence interval does?