Test 3 study guide
which of the following represent a non-directional research hypothesis
The Mu of population A is not equal to the M of population B
Assume that you have conducted a hypothesis test involving a single sample mean with sigma known, and you have used the .05 level of significance in your test. Let's say you had a calculated test statistic of -2.32. Which of the following would be the proper interpretation of your result?
Reject the null hypothesis with the knowledge that there is a 5% chance of having made a type i error (rejection of a true null hypothesis)
Assume that you have conducted a t test with independent samples, and you are using the .01 level of significance. One sample involves 10 cases and the other sample involves 12 cases. You have calculated your test statistic; it is equal to 2.915. Using Appendix B to allow you to find the appropriate critical value, which of the following would be the proper interpretation of your results?
Reject the null hypothesis, with the knowledge that therre is 1% probability of having a type I error
Which of the following would require a two tail test
The Mu of population A is equal to the Mu of population B
Which of the following represent a directional research hypothesis?
The Mu of population A is less than the Mu of population B
Assume that you are conducting a hypothesis test involving a single sample mean with sigma unknown. Which of the following is true with respect to the critical value used in the test?
The critical value at the .01 level of significance will be greater than the critical value at the .05 level of significance.
how do you calculate the number of degrees of freedom for the hypothesis test involving independent samples? (sample A and Sample B)
The degrees of freedom would be equal to the number of cases in Sameple A. minus 1, plus the number of cases in sample B, minus 1..
How do you calculate the number of degrees of freedom fro the hypothesis test involving two matched or related samples?
The degrees of freedom would be equal to the number of differences (i.e., the string of d values) that you calculated, minus 1.
you want to determine if there is a change in perception of voters following exposure to a commercial about candidate x. accordingly, yous elect a sample of 20 registered voters, and you measure the attitude of each voter before and after exposure to the fil by asking each voter to assign the candidate an approval score form 0 to 100. your test is actually based on.
The notion of sampling distribution of mean differences.
An alpha error is:
The rejection of a null hypothesis when it is true
Assume that you have conducted a hypothesis test for a single sample mean with sigma known. Assume also that you are working at the .05 level of significance. Your calculations produce a Z value of +2.13. What should you conclude with respect to the null hypothesis?
With a sample, the critical value would be smaller than the critical value for a sample of 25.
When testing a hypothesis, the level of significance is
the probability of making a type I error
Assume that you have conducted a t test with matched samples. Your test is based upon the before and after scores of 15 research participants, and you have selected the .05 level of significance. You have calculated your test statistic; it is equal to 2.216. Using Appendix B to find the appropriate critical value, which of the following would be the proper interpretation of your results?
Reject the null hypothesis, with the knowledge that there is a 5% probability of having made a type I error.
In the hypothesis test for a single sample mean, when is sigma known?
The z Distribution is known
Assume that you have conducted a hypothesis test involving a single sample mean with sigma unknown, and you have used the .05 level of significance in your test. Let's say you used a sample of 30 cases in your test and you had a calculated test statistic of 1.930. Assuming that the appropriate critical value for your test was 2.045, which of the following would be the proper interpretation of your result?
Fail to reject the null hypothesis
Assume that you have conducted a t test with matched samples. Your test is based upon the before and after scores of 15 research participants, and you have selected the .05 level of significance. You have calculated your test statistic and it is equal to 2.010. Using Appendix B to allow you to find the appropriate critical value, which of the following would be the proper interpretation of your results?
Fail to reject the null hypothesis
Assume that you have conducted a hypothesis test for a single sample mean with sigma known. Assume also that you are working at the .05 level of significance. Your calculations produce a Z value of +2.13. What should you conclude with respect to the null hypothesis?
Reject the null hypothesis with the knowledege thaat there is a .05 probability of making a Type I error
The t test for independent samples
Requires interval/ ratio data and two samples which can have an unequal number of cases
S over D Bar= Sd over square root of n=
The estimate of the standard error of the mean difference
Lauren believes that there has been a significant increase in worker productivity on the part of the team that she supervises, but she wants to carry out some research to be on more solid ground before making that assertion. Given the logic of hypothesis testing, Lauren would actually be testing the idea that:
There has been no change in the level of productivity
Assume that you have conducted a t test with independent samples, and you are using the .05 level of significance. One sample involves 16 cases and the other sample involves 13 cases. You have calculated your test statistic; it is equal to 2.311. Using Appendix B to allow you to find the appropriate critical value, which of the following would be the proper interpretation of your results?
reject the null hypothesis, with the knowledge that there is a 5% probability of having made a type I error
S (sub unit) xbar 1 - xbar 2
the estimate of the standard error of the difference of means
a researcher conducts a test for a related samples and calculates a value of t= 3.24. For the researcher conducting the research, the value of t=3.24 is a statement of:
the calculated test statistic
In statistical terms, effect is defined as:
the change in a measurement that is attributable to a treatment condition or a stimulus of some sort
The failure to reject a false null hypothesis is known as a
type II error
The critical value of t at the .10 level of significance in a two test situation will equal the critical value of t for a one tail test at what level of significance?
.05
The critical value of t at the .10 level of significance in a one tail test situation will equal the critical value of t for a two tail test at what level of significance?
.20
Using Appendix C in your test to assist you, what would be the critical value of t, given a situation in which you were working with a .05 level of significance, 14 degrees of freedom, and a one tail test scenario?
1.761
A statement of no relationship, no difference, no change, or a statement that any relationship, difference or change is due to chance is referred to as:
Null hypothesis
Another name for the critical region is the:
Region of rejection
The power of a statistical test is defined as the ability of a test to:
Reject a null hypothesis when it is false
In the logic of hypothesis testing, which of the following steps is no part of the formal process?
Reject the critical value
A beta error is
The faliure to reject a false null hypothesis
In testing hypothesis, the critical value is the
beginning point of the critical region
In the selection of the critical value in a single sample mean test with sigma unknown, how are degrees of freedom calculated?
n-1
using appendix b i your text to assist you, what would be the appropriate critical at the .05 level of significance, given the following test situation; Test based upon two matched or related samples; 22 cases with 22- pre test scores and 22-post test scores
n-1= 21 = 2.080
The hypothesis that stands in contrast or opposition to the null hypothesis is referred to as the:
research hypothesis
In a single sample mean test with sigma unknown, how do u estimate the value of the standard error
use the standard deviation of the sample, divided by the square root of n
Assume you are conducting a hypothesis test involving a single sample mean with sigma known. You have selected the .05 level of significance. What will be the appropriate critical value that you will use in the test?
1.96
Using appendix B in your test to assist you, what would be the critical value of t, given a situation in which you were working with a .05 significance, 135 degrees of freedom. and a two tailed test scenario
1.960
Using Appendix B in your test to assist you, what would be the critical value of t, given a situation in which you were working with a .05 level of significance, 14 degrees of freedom, and a two tail test scenario?
2.145
Assume you are conducting a hypothesis test involving a single sample mean with sigma known. You have selected the .01 level of significance. What will be the appropriate critical value that you will use in the test?
2.58
In the logic of hypothesis testing, which of the following steps is not part of the formal process
Calculate the level of significance
Assume that you have conducted a hypothesis test for a single sample mean with sigma known. Assume also that you are working at the .01 level of significance. Your calculations produce a Z value of +2.13. What should you conclude with respect to the null hypothesis?
Fail to reject the null hypothesis
a hypothesis tes is used to determine if there is a difference between scores made on a reading comprehension test before and after the students hear a series of lectures in a reading to retain program. the hypothesis test in a situation like that would involve:
the notion of sampling distribution of mean differences
a test to determine if there is a diffrennce between liberal arts and business majors in terms of their scores on a current events test conducted using a sample of 40 liberal arts majors and and a sample of 25 business majors. The test is actually based on:
the notion of sampling distribution of the difference between means
In the hypothesis test for a single sample mean, when is sigma unknown?
the standard error of the mean is estimated