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In a poll of 1000 randomly selected prospective voters in alocal election, 281 voters were in favor of a school bondmeasure.

a. What is the sample proportion? Type as: #.###

b. What is the margin of error for the 90% confidence level?Type as: #.###

c. What is the margin of error for the 95% confidence level?Type as: #.###

d. What is the 95% confidence interval? Type as: [#.###,#.###]

A poll reported a 36% approval rating for a politician with amargin of error of 1 percentage point.

a. How many voters must be sampled for a 90% confidenceinterval? Round up to the nearest whole number.

b. How many voters must be sampled for a 95% confidenceinterval? Round up to the nearest whole number.

Intelligence quotient (IQ) test scores are believed to have amean of 100 and a population standard deviation of 15. In a randomsample of 36 students in a high school, the mean IQ test score is105. Researchers claim that the mean IQ test scores at this highschool is statistically higher than 100.

a. What is the hypothesized mean?

b. Is the hypothesis test two-tailed, right-tailed, orleft-tailed? Type as: two-tailed, left-tailed, or right-tailed

c. What is the z-score?

d. What is the p-value? Type as: #.#####

A transportation commission studies driving times between twocities to determine whether the construction of a new highwayreduced commute times. Times for 40 cars driving on the old highwayand times for 50 cars driving on the new highway are obtained. Asummary of the data obtained from the study is given below.

Highway	Mean commute times	Population standard deviation
1 (Old)	5.35	0.5
2 (New)	4.95	0.8

a. What is the standard error? Type as: #.###

b. What is the z-score? Type as: #.###

c.What is the p-value? Type as: #.######

10,000 individuals are divided evenly into two groups. Thetreatment group is given a vaccine and the control group is given aplacebo. 95 of the 5,000 individuals in the treatment groupdeveloped a disease. 125 of the 5,000 individuals in the controlgroup developed a particular disease. A research team wants todetermine whether the vaccine is effective in decreasing theincidence of disease. Does sufficient evidence exist to concludethat the proportion of developing a disease in individuals giventhe vaccine is less than that of individuals given a placebo?

a. What is the proportion of individuals in the treatment groupthat developed the disease? Type as: #.###

b. What is the proportion of individuals in the control groupthat developed the disease? Type as: #.###

c. What is the proportion of individuals in the overall groupthat developed the disease? Type as: #.###

d. What is the standard error estimate? Type as: #.####

e. What is the z-score? Type as: #.###

f. What is the p-value? Type as: #.####