Problem 3. Of a random sample of 500 Americans, 270 indicated that they would vote for...

Problem 3. Of a random sample of 500 Americans, 270 indicated that they would vote for a Democrat in the upcoming election for president.

Find a 90% confidence interval estimate for the population proportion and interpret it.
A critic claims that the true proportion is .50. Test the validity of this claim against a two- sided alternative at the 10% level of significance. In answering, write out the null and alternative hypotheses in addition to the decision rule. Show your calculations and state your conclusion.
Use your results in part (a) to test the claim. Is your conclusion the same as that in part (b)? Explain clearly.

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Expert Solution

Z test hypothesis for proportion and confidence interval calculation.

orchestra answered 2 years ago

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