um is being held to determine whether the transportation authority should issue additional highway bonds. A sample of 550 voters is taken in county A, and 245 say that they favor the bond proposal. A sample of 600 voters is taken in county B, and 275 say that they favor the bond issue. Perform a hypothesis test to measure the strength of the evidence that the proportion of voters who favor the proposal is greater in county A than in county B. Use the α = 0.02 level of significance.

A random sample of n1 = 148 people ages 16 to 19 were taken from the island of Oahu, Hawaii, and 14 were found to be high school dropouts. Another random sample of n2 = 125 people ages 16 to 19 were taken from Sweetwater County, Wyoming, and 5 were found to be high school dropouts. Do these data indicate that the population proportion of high school dropouts on Oahu is different (either way) from that of Sweetwater County? Use a 1% level of significance.

An automobile dealer conducted a test to determine if the time in minutes needed to complete a minor engine tune-up depends on whether a computerized engine analyzer or an electronic analyzer is used. Because tune-up time varies among compact, intermediate, and full-sized cars, the three types of cars were used as blocks in the experiment. The data obtained follow. Analyzer Computerized Electronic Compact 50 41 Car Intermediate 56 44 Full-sized 62 47 Use a = 0.05 to test for any significant differences. State the null and alternative hypotheses. O Ho: Hcompact * HIntermediate * HFull-sized Ha: "Compact = HIntermediate = 4Full-sized O Ho: HComputerized * HElectronic Ha: HComputerized = HElectronic O Ho: HComputerized = HElectronic Ha: "Computerized * HElectronic O Ho: HComputerized = HElectronic = "Compact = HIntermediate = "Full-sized H.: Not all the population means are equal. O Ho: HCompact = HIntermediate = HFull-sized Hai H compact * HIntermediate * HFull-sized Find the value of…

A study used 1259 patients who had suffered a stroke. The study randomly assigned each subject to an aspirin treatment or a placebo treatment. During a 3-year follow-up period, in Sample 1, 634 people received placebo treatments and 25 people died from heart attack. In sample 2, 625 people received aspirin treatment and 18 died from heart attack. Let pl denote the population proportion of death from heart attack for those with no treatment and p2 denote the population proportion of death from heart attack for those with aspirin treatment. (c) Which of SEO and SE1 is used for calculating a confidence interval for comparing two population proportions? Which is used for calculating the test statistic in a hypothesis test? (d) Construct the 95% confidence interval for pi – p2. Interpret.