Question 1

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

Accepted Answer

The correct notation for the standard error of the mean for a one-sample t test is $s_{\bar{x}}$, which is represented in option D. This notation indicates the standard error calculated from the sample standard deviation (s) for the sample mean ($\bar{x}$).

Question 2

A population has a known mean of 50. A researcher believes that a particular treatment will increase scores and conducts a one-sample t test. What is the null hypothesis?

Accepted Answer

The answer of A population has a known mean of...

Question 3

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?

Accepted Answer

The answer of The population mean for scores on an...

Question 4

A population has a known mean of 62. A researcher implements a new treatment to a sample to determine if it has an effect on the dependent variable. What is the null hypothesis?

Accepted Answer

The answer of A population has a known mean of...

Question 5

A researcher is conducting a one-sample t test to see if a particular intervention has any effect on the dependent variable. Alpha is .05 and n = 18. What is t_crit?

Accepted Answer

The answer of A researcher is conducting a one-sample t...

Question 6

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?

Accepted Answer

The critical t-value for a one-tailed t-test with α = .01 and df = 42 is -2.423. This is because there are 42 degrees of freedom (n-1 = 43-1 = 42) and we are conducting a one-tailed test (looking for decrease in scores). Therefore, the correct answer is A) -2.423.

Question 7

A population has a known mean of 65. A one-sample t test is conducted to determine if a treatment will influence scores on the dependent variable. What is the alternative hypothesis?

Accepted Answer

The alternative hypothesis, denoted by H₁, represents the possibility of there being a difference, relationship, or effect between variables. In this case, we are testing whether the treatment has an influence on the dependent variable, which means we are looking for a difference in scores before and after the treatment. Therefore, the alternative hypothesis is that the population mean is not equal to 65 (since the treatment may increase or decrease scores). Therefore, option B is the correct choice.

Question 8

The population mean on a standardized math test is 75. A tutoring program is implemented at a local college to determine if the math scores would improve as a result. A one-sample t test is conducted. What is the alternative hypothesis?

Accepted Answer

The alternative hypothesis (H₁) should state the possibility of an improvement in math scores, which would mean a higher population mean. Therefore, H₁: μ > 75 is the best choice.

Question 9

A new medication shows promising results in reducing the intensity of symptoms in people who suffer from depression. The population mean on a depression inventory is 25. A one-sample t test is administered to a sample of subjects taking the medication. What is the alternative hypothesis?

Accepted Answer

The answer of A new medication shows promising results in...

Question 10

A population mean is 45. A one-sample t test is conducted with n = 9 subjects and results in a sample mean of 48 with a s = 5. What is t_obt?

Accepted Answer

The t-score is calculated using the formula $t = \frac{\bar{x} - \mu}{(s/\sqrt{n})}$, where $\bar{x}$ is the sample mean, $\mu$ is the population mean, $s$ is the sample standard deviation, and $n$ is the sample size. Plugging in the given values: $t = \frac{48 - 45}{(5/\sqrt{9})} = \frac{3}{(5/3)} = \frac{3}{1.6667} = 1.80$.

Question 11

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?

Accepted Answer

The formula for calculating t_obt is: t_obt = (M - μ) / (s_M/√n) Substituting the given values, we get: t_obt = (81 - 85) / (1.46/√25) t_obt = -4 / 0.292 t_obt = -13.7 The critical value of t for a one-tailed test with 24 degrees of freedom at α = 0.05 is -1.711. Since the calculated t-value (-13.7) is smaller than the critical t-value (-1.711), we reject the null hypothesis. Therefore, the answer is D) -2.74.

Question 12

A one-sample t test is conducted which resulted in a significant effect. The sample mean was 42 based on a sample size of n = 16. The population mean was 50 with s = 2.33. What was Cohen's d effect size?

Accepted Answer

Cohen's d = (M - mu) / s = (42 - 50) / 2.33 = -3.43

Question 13

A one-sample t test was conducted which resulted in a significant effect. The sample mean was 95 based on a sample size of n = 25. The population mean was 90 with an estimated standard deviation of 8.42. What was Cohen's d effect size?

Accepted Answer

Cohen's d effect size can be calculated using the following formula:

d = (sample mean - population mean) / estimated standard deviation

Substituting the values:

d = (95 - 90) / 8.42 
d = 0.59

Since the sample mean is larger than the population mean, the effect size is positive. The correct answer is C, +0.59.

Question 14

Given M = 26, n = 9, μ = 23, and s = 6.2, Cohens's d is _______, which is considered to be a ______________ effect.

Accepted Answer

Cohen's d = (μ - M) / s
Cohen's d = (23 - 26) / 6.2 = -0.48
Since the absolute value of Cohen's d is between 0.2 and 0.5, it is considered to be a small effect size. Therefore, the answer is option A.

Question 15

Which of the following is not one of the assumptions for a one-sample t test?

Accepted Answer

One of the assumptions for a one-sample t test is that the population standard deviation (σ) is unknown and must be estimated from the sample. Therefore, D is the correct answer as it states that σ is known, which is not an assumption for a one-sample t test.

Question 16

When would you use a one-sample t test rather than a z-test?

Accepted Answer

The answer of When would you use a one-sample t...

Question 17

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

Accepted Answer

The answer of How does sample size (and therefore df)...

Question 18

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

Accepted Answer

The answer of What are the two main uses of...

Question 19

Determine t_crit for the following situations and decide if H₀ should be rejected. For the one-tailed tests, assume that the researcher is looking for score increases. $\begin{array}{lcccc} &&&\text { One-or Two- }\ &\underline {\text { df } }&\alpha &\underline {\text { Tailed Test }}& t_{\text { obt }}\ a. & 14 &. 01 & \text { One-tailed} & 2.61\ b. &29&.01& \text { Two-tailed} &2.83 \ c. & 5&.05& \text { One-tailed} & 2.20 \ d. &19 &.05 & \text { Two-tailed }&1.98 \ \end{array}$

Accepted Answer

The answer of Determine t_crit for the following situations and...

Question 20

Describe two potential problems which would make the following conclusion problematic: "The medication had no significant effect. Reject H₀, t(32) = +1.92, p > .05."

Accepted Answer

The answer of Describe two potential problems which would make...

Quiz 9: One-Sample T-Test

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

A population has a known mean of 50. A researcher believes that a particular treatment will increase scores and conducts a one-sample t test. What is the null hypothesis?

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?

A population has a known mean of 62. A researcher implements a new treatment to a sample to determine if it has an effect on the dependent variable. What is the null hypothesis?

A researcher is conducting a one-sample t test to see if a particular intervention has any effect on the dependent variable. Alpha is .05 and n = 18. What is t_crit?

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?

A population has a known mean of 65. A one-sample t test is conducted to determine if a treatment will influence scores on the dependent variable. What is the alternative hypothesis?

The population mean on a standardized math test is 75. A tutoring program is implemented at a local college to determine if the math scores would improve as a result. A one-sample t test is conducted. What is the alternative hypothesis?

A new medication shows promising results in reducing the intensity of symptoms in people who suffer from depression. The population mean on a depression inventory is 25. A one-sample t test is administered to a sample of subjects taking the medication. What is the alternative hypothesis?

A population mean is 45. A one-sample t test is conducted with n = 9 subjects and results in a sample mean of 48 with a s = 5. What is t_obt?

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?

A one-sample t test is conducted which resulted in a significant effect. The sample mean was 42 based on a sample size of n = 16. The population mean was 50 with s = 2.33. What was Cohen's d effect size?

A one-sample t test was conducted which resulted in a significant effect. The sample mean was 95 based on a sample size of n = 25. The population mean was 90 with an estimated standard deviation of 8.42. What was Cohen's d effect size?

Given M = 26, n = 9, μ = 23, and s = 6.2, Cohens's d is _, which is considered to be a ________ effect.

Which of the following is not one of the assumptions for a one-sample t test?

When would you use a one-sample t test rather than a z-test?

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

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

Describe two potential problems which would make the following conclusion problematic: "The medication had no significant effect. Reject H₀, t(32) = +1.92, p > .05."

Quiz 9: One-Sample T-Test

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

A population has a known mean of 50. A researcher believes that a particular treatment will increase scores and conducts a one-sample t test. What is the null hypothesis?

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?

A population has a known mean of 62. A researcher implements a new treatment to a sample to determine if it has an effect on the dependent variable. What is the null hypothesis?

A researcher is conducting a one-sample t test to see if a particular intervention has any effect on the dependent variable. Alpha is .05 and n = 18. What is tcrit?

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 tcrit?

A population has a known mean of 65. A one-sample t test is conducted to determine if a treatment will influence scores on the dependent variable. What is the alternative hypothesis?

The population mean on a standardized math test is 75. A tutoring program is implemented at a local college to determine if the math scores would improve as a result. A one-sample t test is conducted. What is the alternative hypothesis?

A new medication shows promising results in reducing the intensity of symptoms in people who suffer from depression. The population mean on a depression inventory is 25. A one-sample t test is administered to a sample of subjects taking the medication. What is the alternative hypothesis?

A population mean is 45. A one-sample t test is conducted with n = 9 subjects and results in a sample mean of 48 with a s = 5. What is tobt?

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 sM = 1.46. What is tobt?

A one-sample t test is conducted which resulted in a significant effect. The sample mean was 42 based on a sample size of n = 16. The population mean was 50 with s = 2.33. What was Cohen's d effect size?

A one-sample t test was conducted which resulted in a significant effect. The sample mean was 95 based on a sample size of n = 25. The population mean was 90 with an estimated standard deviation of 8.42. What was Cohen's d effect size?

Given M = 26, n = 9, μ = 23, and s = 6.2, Cohens's d is _______, which is considered to be a ______________ effect.

Which of the following is not one of the assumptions for a one-sample t test?

When would you use a one-sample t test rather than a z-test?

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

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

Describe two potential problems which would make the following conclusion problematic: "The medication had no significant effect. Reject H₀, t(32) = +1.92, p > .05."

A researcher is conducting a one-sample t test to see if a particular intervention has any effect on the dependent variable. Alpha is .05 and n = 18. What is t_crit?

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?

A population mean is 45. A one-sample t test is conducted with n = 9 subjects and results in a sample mean of 48 with a s = 5. What is t_obt?

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?

Given M = 26, n = 9, μ = 23, and s = 6.2, Cohens's d is _, which is considered to be a ________ effect.