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 Question from dani, a parent: A poll of 1068 American voters indicated that 48% supported te Democratic candidate for presidency.  At the 0.05 level of significance, test the claim that less than 50% of American voters preferred the Democratic candidate. a. State the null hypothesis b. state the alternaive hypothesis c. find the critical value d. find the vlaue of the test statistic e. find the p-value

Hi Dani,

I can help you get started with this problem. This is a question about the proportion of American voters who preferred the Democratic party at the time the poll was taken. I am going to call this proportion p. The instructions say "test the claim that less than 50% of American voters preferred the Democratic candidate" or, stated using the proportion p, "test the claim that p < 0.5". Hence the hypothesis test is to choose between two alternatives:

p < 0.5 and
p ≥ 0.5

The null hypothesis is always the alternative that contains the equal sign and hence the answer to a. is p ≥ 0.5 and the answer to b. is p < 0.5 .

I hope this helps,
Penny

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