Question: 1 of20 When a p -value is high, this means there is strong evidence against the null hypothesis True False Question 2 of20 In hypothesis
1 of20
When ap-value is high, this means there is strong evidence against the null hypothesis
| True | |
| False |
Question
2 of20
In hypothesis testing, the hypothesis which is tentatively assumed to be true is called the
| correct hypothesis | |
| null hypothesis | |
| alternative hypothesis | |
| level of significance |
Question
3 of20
If ap-value for a 2-sided test equals .065, thep-value for the 1-sided test using the same sample data will not be significant at the 1% level.
| True | |
| False |
Question
4 of20
When a sample statistic is close to the hypothesized population parameter, thep-value for a significance test will typically be low.
| True | |
| False |
Question
5 of20
Which of the following does not need to be known in order to compute theP-value?
| knowledge of whether the test is one-tailed or two-tailed | |
| the value of the test statistic | |
| the level of significance | |
| all of the above are needed |
Question
6 of20
There is a high probability that James Bond can tell the difference between a shaken and a stirred martini.
| True | |
| False |
Question
7 of20
Which of the following is the first step in hypothesis testing?
| It does not matter where you begin when you test hypotheses. | |
| Developing a null and alternative hypothesis. | |
| Drawing a sample from the population. | |
| Setting the cutoff value for rejecting the null hypothesis. |
Question
8 of20
The critical value to be used in a statistical test is determined by the alpha level.
| True | |
| False |
Question
9 of20
Many people describe hypothesis testing as counterintuitive because
| we test whether something happened in order to conclude that nothing happened. | |
| we test whether something happened but can still conclude that nothing happened. | |
| we can only conclude that nothing happened when we are 100% sure that something did not happen. | |
| we test whether nothing happened in order to conclude that something happened. |
Question
10 of20
We always test a null hypothesis against an alternative.
| True | |
| False |
Question
11 of20
The null hypothesis would be rejected if
| the test statistic is less than .05 | |
| the test statistic is greater than .05 | |
| the test statistic is in the rejection region | |
| the test statistic is more than two standard deviations from the mean |
Question
12 of20
Hypotheses in a significance test are always stated in terms of the population parameters.
| True | |
| False |
Question
13 of20
What is being addressed by a one-sample hypothesis test?
| Does our sample come from a particular population? | |
| Does our sample have the same variance as another population? | |
| Is our sample unusual in some way? | |
| Does the five-number summary of our sample match that of a particular population? |
Question
14 of20
Let's suppose we conduct a hypothesis test about the mean value of something, and determine that we should reject the null hypothesis. What does that mean?
| Our hypothesized mean has been proven incorrect. | |
| The difference between our sample mean and our hypothesized mean was most likely due to random chance. | |
| The difference between our sample mean and our hypothesized mean was statistically significant. | |
| The difference between our sample mean and our hypothesized mean was not statistically significant. |
Question
15 of20
Given a statistical test scenario with alpha set to .05 the absolute value of the critical value is determined to be 1.96. What does that also tell you about the hypothesis?
| It is likely that the null will not be rejected because the rejection region is too narrow. | |
| It is likely that a decision error will be made. | |
| The test is two-tailed. | |
| can't really say that it tells me anything |
Question
16 of20
The formula is used to calculate
| the z-score of a data point. | |
| the z-score of a sample mean. | |
| the z-score of a sample proportion. | |
| none of the above |
Question
17 of20
When testing a sample mean against a known population parameter thet-distribution is used when
| sis used as an estimate of | |
| x is used as an estimate of | |
| the sample size is small | |
| dfare unknown |
Question
18 of20
t-tables typically show
| the area above thet-score | |
| the area below thet-score | |
| critical values oft | |
| z-score equivalents |
Question
19 of20
A statistics professor announces to the class that a majority of students who take his class earn an A. A skeptical group of students suspects that this is too good to be true. If they were going to conduct a hypothesis test, what would the appropriate hypotheses be?
| Ho: 0.50, Ha: = 0.50 | |
| Ho: 0.50, Ha: < 0.50 | |
| Ho: < 0.50, Ha: > 0.50 | |
| Ho: = 0.50, Ha: > 0.50 |
Question
20 of20
It is claimed that 66% of Boston residents have considered moving to a warmer climate. A group of city council members is hoping that the actual figure is lower than that, and wish to conduct a hypothesis test at the =.05 level of significance to determine if they are right. Which would be correct hypotheses for this test?
| Ho: 0.66, Ha: < 0.66 | |
| Ho: 0.66, Ha: > 0.66 | |
| Ho: < 0.66, Ha: = 0.66 | |
| Ho: = 0.66, Ha: 0.66 |
1 of20
Voter registration records are compared to see if Yuma County has a higher proportion of registered voters than Pinal County. What is the appropriate statistical test?
| t-test for independent samples | |
| t-test for dependent samples | |
| z-test for proportions |
Question
2 of20
Why do we use the t-distribution instead of the normal distribution as our reference distribution?
| The population variances are unknown and we are estimating them from a sample. | |
| You never use the normal distribution in applied statistics | |
| Because our sample size is large. | |
| Since we are using the standard deviation instead of the variances in our calculations |
Question
3 of20
In order to test whether there is a difference between two population means, an assumption is that
| we have two scores, or values, per subject | |
| 1 2 | |
| each value is sampled independently from each other value | |
| samples are dependent |
Question
4 of20
Is there a statistically significant difference (p < .05) between the average wait times at these two doctor's offices? Below are 10 wait times in minutes.
Dr. Strangelove: 12 17 21 22 29 18 13 25 20 27 Dr. Zhivago: 23 24 27 27 26 26 31 29 23 23
| The test statistic of 2.78 is greater than .05 so we conclude the difference is statistically significant. | |
| You can't use the 2-sample t-test unless the sample size is greater than 30. | |
| The difference in wait times of 5.5 minutes is *NOT* statistically significant because the p-value of .0156 is less than .05. | |
| The difference in wait times of 5.5 minutes is statistically significant because the p-value of .0156 is less than .05. |
Question
5 of20
The statistical test for comparing the means of two matched samples uses the normal distributions.
| True | |
| False |
Question
6 of20
If you test for the difference between the means of two independent samples, there are how many degrees of freedom?
| (n1 + n2) / 2 - 1 | |
| n1 + n2 - 2 | |
| (n1 + n2) / 2 | |
| n -1 |
Question
7 of20
When testing for differences between the means of two related populations, what is the null hypothesis?
| The difference between the population means is equal to 0. | |
| The difference between the population means is equal to 1. | |
| The difference between the population means is greater than 1. | |
| The difference between the population means is greater than 0. |
Question
8 of20
When conducting a two-sample test of proportions, the difference between the population proportions
| is unknown | |
| is equal to p1- p2 | |
| is assumed to be zero under the null hypothesis | |
| is unimportant |
Question
9 of20
What does p (p-bar) represent?
| the weighted average of the sample proportions of successes | |
| the sample proportions of successes | |
| the population proportions of successes | |
| the number of successes in each sample |
Question
10 of20
A _______ standard deviation in the population will result in a larger effect size.
| larger | |
| smaller | |
| more clearly defined | |
| less clearly defined |
Question
11 of20
As sample size is increased
| the likelihood of a statistically significant result increases. | |
| the likelihood of a statistically significant result decreases. | |
| effect size determination becomes irrelevant. |
Question
12 of20
A calculated value of d = .45 indicates
| a small effect size | |
| a medium effect size | |
| a large effect size | |
| a significant effect size |
Question
13 of20
In hypothesis testing, beta is
| the probability of committing a Type II error | |
| the probability of committing a Type I error | |
| the probability of either a Type I or Type II, depending on the hypothesis to be tested | |
| none of the above |
Question
14 of20
When the null hypothesis has been true, but the sample information has resulted in the rejection of the null, a _________ has been made.
| level of significance | |
| Type II error | |
| critical value | |
| Type I error |
Question
15 of20
A Type II error occurs when
| we correctly fail to reject a false null hypothesis. | |
| we incorrectly fail to reject a false null hypothesis | |
| we incorrectly reject a true null hypothesis. | |
| we correctly reject a false null hypothesis. |
Question
16 of20
A Type I error occurs when we
| correctly fail to reject a false null hypothesis. | |
| correctly reject a false null hypothesis. | |
| incorrectly reject a false null hypothesis. | |
| incorrectly reject a true null hypothesis. |
Question
17 of20
The maximum probability of a Type I error that the decision maker will tolerate is called the
| level of significance | |
| critical value | |
| decision value | |
| probability value |
Question
18 of20
The power of a test is
| the probability of declaring a difference that does not actually exist | |
| the probability of finding a difference that does exist | |
| the probability of incorrectly rejecting Ho | |
| the probability of rejecting Ha when it is false |
Question
19 of20
If "going to the doctor" is used as an analogy, then power is
| your doctor confirming that you really are sick. | |
| getting scared for nothing. | |
| your doctor stating you are not sick when there is nothing wrong. | |
| your doctor is missing a real illness. |
Question
20 of20
Two-tailed hypothesis tests have ________ power than one-tailed tests.
| slightly more | |
| slightly less | |
| more | |
| less |
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