For a given level of significance, the critical value of Student's t increases as n increases

For a sample of nine items, the critical value of Student's t for a left-tailed test of a mean at α= .05 is -1.860

Holding other factors constant, it is harder to reject the null hypothesis for a mean when conducting a two-tailed test rather than a one-tailed test

In a right-tailed test, the null hypothesis is rejected when the value of the test statistic exceeds the critical value.

If we desire α= .10, then a p-value of .13 would lead us to reject the null hypothesis.

The p-value is the probability of the sample result (or one more extreme) assuming H0 is true

The probability of rejecting a true null hypothesis is the significance level of the test

A null hypothesis is rejected when the calculated p-value is less than the critical value of the test statistic

Hypothesis testing is a procedure based on sample evidence and probability theory to decide whether the hypothesis is a reasonable statement.

Generally speaking, the alternate hypothesis is set up for the purpose of either accepting or rejecting it.

The level of significance refers to the probability of making a Type I error.

A Type I error probability is represented by α, it is the probability of incorrectly rejecting a null hypothesis that is true

Type I errors are usually considered more "costly" although this can lead to conservative decision making

The probability of making a Type I error and the level of significance are the same.

A Type II error is committed when we incorrectly accept an alternative hypothesis that is false

If the null hypothesis is false and the researchers do not reject it, then a Type I error has been made

Type II error is the probability or risk assumed by rejecting a null hypothesis when it is actually true

The power of a test is the probability of rejecting the null hypothesis when the alternative hypothesis is true

The analyst gets to choose the significance level . It is typically chosen to be 0.50, but it is occasionally chosen to be 0.05

The significance level also determines the rejection region

The p-value of a test is the probability of observing a test statistic at least as extreme as the one computed given that the null hypothesis is true.

A low p-value provides evidence for accepting the null hypothesis and rejecting the alternative

The test statistic for a hypothesis test of a population proportion is the z -value

If the null hypothesis is and the alternate hypothesis states that is less than 200, then, a two-tail test is being conducted

A p-value is the same as a stated significance level

Assuming that the null hypothesis is true, a p-value is the probability of observing a sample value greater than and/or less than an observed sample observation

A hypothesis test may be statistically significant, yet have no practical significance.

For a given level of significance (α), increasing the sample size will increase the probability of Type II error because there are more ways to make an incorrect decision.

For a given sample size, the probability of committing a Type II error will increase when the probability of committing a Type I error is reduced

A smaller probability of Type II error implies higher power of the test

In hypothesis testing, we are trying to reject the alternative hypothesis

Which of the following is not a valid null hypothesis?

For a given sample size, when we increase the probability of Type I error, the probability of a Type II error:

After testing a hypothesis, we decided to reject the null hypothesis. Thus, we are exposed to:

Which of the following is correct?

Which of the following is incorrect?

If an economist wishes to determine whether there is evidence that average family income in a community exceeds $25,000

If an economist wishes to determine whether there is evidence that average family income in a community equals $25,000

If a test of hypothesis has a Type I error probability of 0.01, we mean

For a given sample size n , if the level of significance α is decreased, the power of the test

Which of the following statement is correct?

A two-sided or two-tailed hypothesis test is one in which

Null and alternative hypotheses are statements about

Which statement is correct about a p-value?

A hypothesis test gives a p-value of 0.03. If the significance level α = 0.05, the results are said to be

The likelihood that a statistic would be as extreme or more extreme than what was observed is called a

The designated level (typically set at 0.05) to which the p-value is compared to, in order to decide whether the alternative hypothesis is accepted or not is called a

"Currently, only 20% of arrested drug pushers are convicted," cried candidate Courageous Calvin in a campaign speech. "Elect me and you'll see a big increase in convictions." A year after his election a random sample of 144 case files of arrested drug pushers showed 36 convictions. For a right-tailed test, the p-value is approximately

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. If she wants to be 99% confident in her decision, what rejection region should she use?

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to be 99% confident in her decision, what decision should she make?

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. If she wants to be 99% confident in her decision, what conclusion can she make ?

The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is over 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 30.45 years and the sample standard deviation was 5 years. What is the p-value associated with the test statistic?

The owner of a local nightclub has recently surveyed a random sample of n= 300 customers of the club. She would now like to determine whether or not the mean age of her customers is over 35. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. Suppose she found that the sample mean was 35.5 years and the population standard deviation was 5 years. What is the p-value associated with the test statistic?

A two-tailed hypothesis test for H0: π= .30 at α= .05 is analogous to

For a right-tailed test of hypothesis for a population mean with known σ, the test statistic was z=1.79. The p-value is:

If n= 25 and α= .05 in a right-tailed test of a mean with unknown σ, the critical value is:

Which of the following statements is correct?

Select one:

For a right-tailed test of a hypothesis for a population mean with n= 14, the value of the test statistic was t= 1.863. The p-value is:

Hypothesis tests for a mean using the critical value method require:

The critical value in a hypothesis test:

Which is not a likely reason to choose the z distribution for a hypothesis test of a mean?

Dullco Manufacturing claims that its alkaline batteries last at least 40 hours on average in a certain type of portable CD player. But tests on a random sample of 18 batteries from a day's large production run showed a mean battery life of 37.8 hours with a standard deviation of 5.4 hours. To test DullCo's hypothesis, the test statistic is:

Last year, 10 percent of all teenagers purchased a new iPhone. This year, a sample of 260 randomly chosen teenagers showed that 39 had purchased a new iPhone. The test statistic to find out whether the percent has risen would beSelect one:

Last year, 10 percent of all teenagers purchased a new iPhone. This year, a sample of 260 randomly chosen teenagers showed that 39 had purchased a new iPhone. To test whether the percentage has risen, the critical value at α= .05 is:

Last year, 10 percent of all teenagers purchased a new iPhone. This year, a sample of 260 randomly chosen teenagers showed that 39 had purchased a new iPhone. To test whether the percentage has risen, the p-value is approximately:

Ajax Peanut Butter's quality control allows 2 percent of the jars to exceed the quality standard for insect fragments. A sample of 150 jars from the current day's production reveals that 30 exceed the quality standard for insect fragments. Which is incorrect?

In the nation of Gondor, the EPA requires that half the new cars sold will meet a certain particulate emission standard a year later. A sample of 64 one-year-old cars revealed that only 24 met the particulate emission standard. The test statistic to see whether the proportion is below the requirement is:

At α= .05, the critical value to test the hypotheses H0: π≥ .40, H1: π< .40 would be:

Which of the following decisions could result in a Type II error for a test?

Which statement about α is not correct?

John rejected his null hypothesis in a right-tailed test for a mean at α = .025 because his critical t value was 2.000 and his calculated t value was 2.345. We can be sure that: