An automotive expert claims that the large number of self-serve gasoline stations has resulted in poor automobile maintenance, and that the average tire pressure is more than 4 pounds per square inch (psi) below its manufacturer’s specification. As a quick test, 50 tires are examined, and the number of psi each tire is below specification is recorded. If we assume that tire pressure is normally distributed with σ = 1.5 psi, can we infer at the 10% significance level that the expert is correct? What is the p-value?
Answer to relevant QuestionsFor the past few years, the number of customers of a drive-up bank in New York has averaged 20 per hour, with a standard deviation of 3 per hour. This year, another bank 1 mile away opened a drive-up window. The manager of ...The test of hypothesis in the SSA example concluded that there was not enough evidence to infer that the plan would be profitable. The company would hate to not institute the plan if the actual reduction was as little as 3 ...a. The mean and standard deviation of a sample of 100 are x̄ = 10 and s = 1.Estimate the population mean with 95% confidence.b. Repeat part (a) with s = 4.c. Repeat part (a) with s = 10.d. Discuss the effect on the ...a. To test the following hypotheses, a statistics practitioner randomly sampled 100 observations and found x̄ = 106 and s = 35. Calculate the test statistic (and for Excel users, the p-value) of a test to determine whether ...A courier service advertises that its average delivery time is less than 6 hours for local deliveries. A random sample of times for 12 deliveries to an address across town was recorded. These data are shown here. Is this ...
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