Part 1.
1. A polling firm conducted a poll of 1000 randomly selected Georgia Stat University students and discovered that 47% of them voted for Bush in 2004. Nationwide Bush received 51.2% of the popular vote. Using this information, evaluate the hypothesis that Georgia State students were significantly less likely to vote for Bush than the national average.
2. An engineer has designed a new type of light bulb. The mean lifetime for the standard bulb is 1200 hours. A test of 400 bulbs of the new type produces a mean of 1206 hours, with a standard deviation of 80 hours. Evaluate the hypothesis that the new type of bulb is better (lasts longer) than the old type.
Part 2.
Questions 3-5 refer to the following table, which reports the results of a survey taken during Barry Bonds pursuit of Hank Aarons home run record. CBS News conducted a poll in which it asked respondents "Are you rooting for Barry Bonds to break Hank Aarons home run record?" The following table displays the number of people who supported and did not support Barry Bonds, grouped by the respondent's age.
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18-44
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44& older
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Rooting
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237
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122
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Not tooting
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165
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135
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Don't care
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149
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194
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3. Rewrite the table as a cross the crosstabtabulation with the appropriate percentages. Just from looking at the crosstab, is there a relationship between age and support of Bonds? If so, what is it?
4. Calculate and interpret the appropriate measure of association.
The appropriate measure of association is chi square test of independence of attributes. The chi-squared test of independence is used when you have two attribute variables, each with two or more possible values.
Calculation of chi square statistic
5. Test the null hypothesis that there is no difference between the two age groups by conducting a difference-in-proportions test on the proportion of people who are rooting for Bonds.