| In 1965, about 44% of the U.S. adult population had never smoked cigarettes. A national health survey of 1472 U.S. adults (presumably selected randomly) during 2010 revealed that 677 had never smoked cigarettes. Suppose you wished to test whether there has been a change since 1965 in the proportion of U.S. adults that have never smoked cigarettes. You suspect that the proportion has grown since 1965. Which of the following are the appropriate hypotheses? | A. Ho: p= 0.44, Ha: p >0.44 | | B. Ho: p = 0.44, Ha: p 0.44 | | C. Ho: p= 0.44, Ha: p 0.44 | | D. Ho: p= 0.51, Ha: p 0.51 | Reset Selection |
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| Question 7 of 10 | 1.0 Points |
A candidate for one of Ohios two U.S. Senate seats wishes to compare her support among registered voters in the northern half of the state with her support among registered voters in the southern half of the state. A random sample of 2000 registered voters in the northern half of the state is selected, of which 1062 support the candidate. Additionally, a random sample of 2000 registered voters in the southern half of the state is selected, of which 900 support the candidate. For purposes of comparing the two proportions, the sampling distribution for the difference in the sample proportions has standard error | A.0.022 | | B.0.0002 | | C.0.300 | | D.0.016 | Reset Selection | | Question 8 of 10 | 1.0 Points |
A candidate for one of Ohios two U.S. Senate seats wishes to compare her support among registered voters in the northern half of the state with her support among registered voters in the southern half of the state. A random sample of 2000 registered voters in the northern half of the state is selected, of which 1062 support the candidate. Additionally, a random sample of 2000 registered voters in the southern half of the state is selected, of which 900 support the candidate. Using the large-sample estimate, we estimate that the proportion of registered adults in the southern half of the state who support this candidate is | A.0.375 | | B.0.183 | | C.0.450 | | D.0.825 | Reset Selection | |
| Part 4 of 4 - Random draw from Ch 21 |
| Question 9 of 10 | 1.0 Points |
In a large university (the class of entering first year is 6000 or more students), an SRS of 100 entering first year in 1999 found that 20 finished in the bottom third of their high school class. Admission standards at the university were tightened in 1995. In 2001, an SRS of 100 entering first year found that 10 finished in the bottom third of their high school class. Letp1andp2be the proportion of all entering first year in 1999 and 2001, respectively, who graduated in the bottom third of their high school class. Is there evidence that the proportion of freshmen who graduated in the bottom third of their high school class in 2001 has been reduced, as a result of the tougher admission standards adopted in 2000, compared to the proportion in 1999? To determine this, you test the hypothesesHo:p1=p2,Ha:p1>p2. The value of thezstatistic for testing these hypotheses is | A. z= 1.65 | | B. z= 1.20 | | C. z= 1.96 | | D. z= 1.98 | Reset Selection | | Question 10 of 10 | 1.0 Points |
In the past decades there have been intensive antismoking campaigns sponsored by both federal and private agencies. In one study of national smoking trends, two random samples of U.S. adults were selected in different years: The first sample, taken in 1995, involved 4276 adults, of which 1642 were smokers. The second sample, taken in 2010, involved 3908 adults, of which 1415 were smokers. The samples are to be compared to determine whether the proportion of U.S. adults that smoke declined during the 15-year period between the samples. Letp1be the proportion of all U.S. adults that smoked in 1995. Letp2denote the proportion of all U.S. adults that smoked in 2010. Thep-value of the test for equality of the proportion of smokers in 1995 and 2010 is | A.greater than 0.10 | | B.between 0.01 and 0.05 | | C.between 0.05 and 0.10 | | D.below 0.01 | | |
