Exam
Name___________________________________

SHORT ANSWER.  Write the word or phrase that best completes each statement or answers the question.
Test the claim that the samples come from populations with the same mean. Assume that the populations are normally distributed with the same variance.
1) At the 0.025 significance level, test the claim that the four brands have the same mean if the following sample results have been obtained.
	         	1)  _____________

Use the traditional method to test the given hypothesis. Assume that the samples are independent and that they have 
2) In a random sample of 360 women, 65% favored stricter gun control laws. In a random sample of 220 men, 60% favored stricter gun control laws. Test the claim that the proportion of women favoring stricter gun control is higher than the proportion of men favoring stricter gun control. Use a significance level of 0.05.	2)  _____________

Test the indicated claim about the means of two populations. Assume that the two samples are independent simple random samples selected from normally distributed populations. Do not assume that the population standard deviations are equal.  Use the traditional method or P-value method as indicated.
3) A researcher wishes to determine whether people with high blood pressure can reduce their blood pressure, measured in mm Hg, by following a particular diet. Use a significance level of 0.01 to test the claim that the treatment group is from a population with a smaller mean than the control group. Use the traditional method of hypothesis testing.

	n1 = 35	n2 = 28
	 = 189.1 	 = 203.7 
	s1 = 38.7 	s2 = 39.2 	3)  _____________

Use the traditional method of hypothesis testing to test the given claim about the means of two populations. Assume that two dependent samples have been randomly selected from normally distributed populations.
4) The table below shows the weights of seven subjects before and after following a particular diet for two months.
	
Using a 0.01 level of significance, test the claim that the diet is effective in reducing weight.	4)  _____________

1)   μ1 = μ2 = μ3 = μ4.   The means are not all equal. P-value p = 0.00285.
Test statistic F = 6.6983. Critical value F = 3.9034.
Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that the four brands have the same mean.
2) H0 p1 = p2.		H1 p1 > p2.
Test statistic z = 1.21.	Critical value z = 1.645.
Fail to reject the null hypothesis. There is not sufficient evidence to support the claim that the proportion of women favoring stricter gun control is higher than the proportion of men favoring stricter gun control.
3) H0 μ1 = μ2.		
H1 μ1 < μ2.
Test statistic t = -1.477. 
Critical value -2.473.
Do not reject the null hypothesis. There is not sufficient evidence to support the claim that the treatment group is from a population with a smaller mean than the control group.
4) H0 μd = 0.  H1 μd > 0. 
Test statistic t = 1.954. Critical value t = 3.143.
Fail to reject H0. There is not sufficient evidence to support the claim that the diet is effective in reducing weight.