Exam 9: One-Sample T-Test

A researcher wants to conduct a one-sample t test on a population that has a μ = 35. He believes that he has an intervention which will increase scores. State the null and alternative hypotheses in symbolic notation.

Write tcrit for each of the following situations: a. n = 22; α = .05, two-tailed b. n = 36; α = .01, two-tailed c. n = 16; α = .05, one-tailed (the researcher believes treatment will increase scores) d. n = 9; α = .10, one-tailed (the researcher believes treatment will decrease scores)

A population mean is μ = 85. A one-sample t test is conducted with n = 25 subjects. The test resulted with a sample mean of M = 81 and s_M = 1.46. What is t_obt?

How does sample size (and therefore df) affect the ability to reject the null hypothesis of a t test?

For a one-sample t test, H₀: μ = 20. Given M = 18, s = 3, and n = 12, what is t_obt?

An obtained probability for a t test that is less than alpha

If the results of a t test include the statement that "p > .01," then

An obtained probability for a t test that is greater than alpha

A student success coach enlisted the assistance of the college's statistician to determine if her new study skills program will have any effect on entrance exam scores. The mean on the exam for new students who do not go through the program is μ = 76. The program is implemented over the summer before classes start in the fall. A sample of these students are tested and obtain a M = 79. a. Write the null and alternative hypotheses in words. b. Write the null and alternative hypotheses in symbolic notation.

A normally distributed population has a μ = 100. After a treatment procedure is implemented to a sample of size n = 36, a sample mean of M = 91 is obtained with a s = 20. Did treatment significantly lower scores? Test at α = .01.

A researcher is conducting a one-sample t test to determine if a particular treatment intervention will lower scores on a dependent variable. α = .01 and n = 43. What is t_crit?

Which of the following is false regarding the table for the t-distribution?

The population mean for scores on an anxiety scale is 28. A researcher obtains a representative sample and implements a treatment designed to decrease anxiety scores. A one-sample t test is conducted. What is the null hypothesis?

Fear of public speaking is reported to be one of the greatest fears that people have. The population mean on a public speaking anxiety scale is μ = 50. A performing arts instructor believes that students who major in the theater have less anxiety about public speaking than the general population. She decides to test her hypothesis by administering the public speaking anxiety test to a sample of theater majors. A sample mean of M = 48 is obtained. a. Write the null and alternative hypotheses in words. b. Write the null and alternative hypotheses in symbolic notation.

An obtained t-value that falls close to the population mean

What are the two main uses of the one-sample t test?

A population has a known mean of 98 with s = 18. Can H₀ be rejected at a .05 level of significance, two-tailed, if M = 104 with a sample size of 64?

The t-distribution is a family of curves. The particular t-distribution that is used for a hypothesis test will be based on ________________.

Which is the correct notation for the standard error of the mean for a one-sample t test?

A particular make and model of an automobile is advertised to get 36 miles per gallon (MPG) of gasoline. A representative from a "Truth in Advertising" organization samples 5 vehicles of that make and model which earned the following MGP scores: 38, 40, 35, 37, and 41. Conduct a one-sample t test to determine if the MPG of the sample models differs significantly from that which was advertised. Use α = .05.