BUAL 2650 FINAL EXAM

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BUAL 2650 FINAL EXAM

ACTUAL EXAM WITH CORRECT SOLUTIONS.

Suppose that a random variable x has a uniform distribution with c = 2 and d =8. Find P(3 <= x <= 5) - correct answer- .333

Find the area under the normal curve when P(Z > -2) - correct answer- .9772

Find the area under the normal curve between P(1 < z <2) - correct answer- .1359

In a manufacturing process, we are interested in measuring the average length of a certain type of bolt. Past data indicate that the standard deviation is .25 inches. How many manufactured bolts should be sampled in order to make us 95 percent confident that the sample mean bolt length is within .02 inches of the true mean bolt length? - correct answer- 601

Rejecting a true null hypothesis is called a ________ error. - correct answer- Type 1

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A recent study conducted by the state government attempts to determine whether the voting public supports a further increase in cigarette taxes. The opinion poll recently sampled 1,500 voting-age citizens. 1,020 of the sampled citizens were in favor of an increase in cigarette taxes. The state government would like to decide if there is enough evidence to establish whether the proportion of citizens supporting an increase in cigarette taxes is significantly greater than .66. Identify the null hypothesis. - correct answer- p ≤ .66

In testing H0: μ= 23; versus HA: μ > 23 using the critical value rule, when x¯ = 26, s = 6, and n = 20, what is the value of the test statistic? Assume that the population from which the sample is selected is normally distributed. - correct answer- 2.24

In a manufacturing process, a random sample of 36 manufactured bolts has a mean length of 3 inches with a standard deviation of .3 inches. What is the 99 percent confidence interval for the true mean length of the manufactured bolt? - correct answer- 2.228 to 3.772

A confidence interval for the population mean is an interval constructed around the ________. - correct answer- sample mean

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