An opinion poll asked a random sample of high school couples in the United States whether they believe they will marry their high school sweetheart. A researcher believes more than 25% of high school couples believe they will marry. Which null and alternative hypotheses should be used to test this claim? (4 points)

	H0: p = 0.25, Ha: p > 0.25
	H0: p = 0.25, Ha: p < 0.25
	H0: p = 0.25, Ha: p 0.25
	H0: p > 0.25, Ha: p = 0.25
	H0: p 0.25, Ha: p > 0.25

2.

(06.01 MC) A student performs a test of H₀: p = 0.5 versus H_a: p < 0.5 and gets a p-value of 0.35. The student writes: "Because the p-value is less than 0.5, we reject the null hypothesis." What is wrong with the student's conclusion? (4 points)

	The student should have stated the data prove Hais true.
	The student should have stated the data prove H0is true.
	The p-value should be compared with the mean, not the hypothesized value of p.
	The p-value should be compared with the standard deviation, not the hypothesized value of p.
	The p-value should be compared with a significance level such as = 0.05, not the hypothesized value of p.

3.

(06.02 LC) In a test of the hypothesis H₀: p = 0.6 against H_a: p > 0.6, the power of the test when p = 0.7 is greatest for which of the following? (4 points)

	n = 45, = 0.10
	n = 45, = 0.05
	n = 50, = 0.10
	n = 50, = 0.05
	There is not enough information given to draw a conclusion.

4.

(06.02 MC) Suppose a political advisor is interested in the proportion of the vote an opponent will receive. If he samples voters randomly and tests hypotheses regarding p, the population proportion, what should he do to reduce his risk of making a Type II error?(4 points)

1. Increase the number of voters he will sample
2. Decrease the number of voters he will sample
3. Increase the significance level
4. Decrease the significance level

	I only
	II only
	III only
	II and IV only
	I and III only

5.

(06.02 MC) Officials of a hunting club want to know whether more than 60% of members support a 1% increase in monthly dues to fund a hunting trip across the country. Club officials survey a random sample of 100 members and use the results to test the hypotheses H0: p = 0.60 and H_a: p > 0.60, where p is the proportion of all members who support a 1% increase in monthly dues to fund a cross-country trip. In the context of this study, how could a Type II error occur? (4 points)

	The hunting club officials find evidence that more than 60% of members support the dues increase, when there isn't evidence that more than 60% support the increase.
	The hunting club officials find convincing evidence that more than 60% of members support the dues increase, when at most, 60% of the members support the increase.
	The hunting club officials find evidence that more than 60% of members supports the monthly increase, when more than 60% of the members do support the increase.
	The hunting club officials do not find evidence that more than 60% of members support the dues increase, when more than 60% of the members do support the increase.
	The hunting club officials do not find evidence that more than 60% of members support the dues increase, when at most, 60% of the members do support the increase.

6.

(06.02 MC) An individual is arrested for stalking and pleads not guilty at trial. The jury can only find her guilty if there is evidence beyond a reasonable doubt to reject the assumption of innocence. Describe what could occur if the jury makes a Type II error? (4 points)

	The jury finds the individual innocent and she is released from jail, but she is actually guilty.
	The jury finds the individual guilty, she is put in jail, and she is actually guilty.
	The jury finds the individual innocent, she is released from jail, and she is actually innocent.
	The jury finds the individual guilty and she is put in jail, but she is actually innocent.
	A conclusion cannot be made based on the information given.

7.

(06.04 MC) A poll of 1,000 randomly selected registered voters was taken and 584 responded that they favor candidate X for governor (p₁= 0.5840). Just before the election, another poll of 950 registered voters was taken and 401 individuals responded that they favor candidate X (p₂= 0.4221). A 95% two-proportion z confidence interval for the true difference betweenp₁andp₂was found to be (0.1181, 0.2057). What is the meaning of the interval in the context of the problem? (4 points)

	There has been a substantial gain in support for the candidate.
	There has been a substantial drop in support for the candidate.
	There has been no change in support for the candidate.
	It is probable for the candidate to get most of the votes because the confidence interval is positive.
	It is not probable for the candidate to get most of the votes because support has dropped below 50%.

8.

(06.04 LC) A recent study states that high winds can affect the pollination rate of sunflowers. It reported that 52 of 60 sunflower plants that were shielded from high winds pollinated and 41 of 55 sunflower plants left unshielded were pollinated. Choose the 98% confidence interval that represents the difference between the proportions of shielded and unshielded sunflower plants that are pollinated. (4 points)

9.

(06.05 MC) A researcher wants to conduct a study to determine whether a newly developed antidrug program is successful. Two randomly selected groups of 250 students each, identified as control and treatment groups, are formed from the 500 students accused of using drugs. Both groups receive a set of antidrug materials and a lecture from a teacher and an ex-drug user about the dangers of drug use. In addition, the treatment group also receives materials from the newly developed program. One hundred forty-eight of the 250 students in the control and 175 of the 250 students in the treatment group no longer use drugs is recorded 9 months later. Use the results to test the hypotheses H₀: p₁= p₂and H_a: p₁ p₂where p₁represents the proportion of students who succeed in the control program and p2 represents the proportion of students who succeed in the newly developed program. What can you conclude using the significance level = 0.05? (5 points)

	The new antidrug program is not significantly different than the control program at reducing drug use because the p-value is less than = 0.05.
	The new antidrug program is effective at reducing drug use because the proportion of students who no longer use drugs is greater in the treatment group than control group.
	The new antidrug program is significantly different than the control program at reducing drug use because the p-value is less than = 0.05.
	The new antidrug program is not significantly different than the control program at reducing drug use because the difference in the proportions of the control group and treatment group is small.
	The new antidrug program is effective at reducing drug use because the standard deviation is small, 0.0764.

10.

(06.05 MC) The way in which response options are presented in a question can affect a person's response. Four hundred randomly selected people were asked about their ketchup or mustard preference. Two hundred of the participants were randomly given the option of ketchup first and the remaining 200 participants were given the option of mustard first. The results are given in the table.

To conclude if the order in which options are presented in a question affects the answer, a two-proportion z-test was conducted. What is the correct p-value of the test? (4 points)

	0.0599
	0.2419
	0.4838
	0.5125
	0.6169

11.

(06.05 LC) You want to find out if the proportion of female college students who had a scholarship during the past semester is greater than the proportion of male college students who had a scholarship during the past semester. Out of a simple random sample of 400 female and 450 male college students, you find that 305 females and 326 males reported they had a scholarship the previous semester. Which hypotheses should you test if p_mand p_fdenote the proportions of all college males and females, respectively, who had a scholarship the previous semester? (5 points)

	H0: pm pf= 0 versus Ha: pm pf 0
	H0: pm pf= 0 versus Ha: pm pf> 0
	H0: pm pf= 0 versus Ha: pm pf< 0
	H0: pm pf> 0 versus Ha: pm pf= 0
	H0: pm pf 0 versus Ha: pm pf= 0

12.

(06.05 MC) Which of the following is a TRUE statement about hypothesis testing? (4 points)

	If there is sufficient evidence to reject a null hypothesis at the 10% level, then there is sufficient evidence to reject it at the 5% level.
	Whether to use a one-sided or a two-sided test is typically decided before the data are gathered.
	If a hypothesis test is conducted at the 1% level, there is a 1% chance of rejecting the null hypothesis.
	The probability of a Type I error plus the probability of a Type II error always equals one.
	The power of a test concerns its ability to detect a null hypothesis.