BUAL 2650 Final Exam || with 100% Error-free Solutions.
Suppose that a random variable x has a uniform distribution with c = 2 and d =8. Find P(3 <= x
<= 5) correct answers .333
Find the area under the normal curve when P(Z > -2) correct answers .9772
Find the area under the normal curve between P(1 < z <2) correct answers .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 answers 601
Rejecting a true null hypothesis is called a ________ error. correct answers Type 1
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 answers 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 answers 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 answers 2.228 to 3.772
A confidence interval for the population mean is an interval constructed around the ________.
correct answers sample mean
When the population is normally distributed, population standard deviation σ is unknown, and
the sample size is n = 15, the confidence interval for the population mean μ is based on the z
(normal) distribution. correct answers the t distribution
The exact spread of the t distribution depends on the ________. correct answers number of
degrees of freedom
______ says that if the sample size is sufficiently large, then the sample means are approximately
normally distributed. correct answers The Central Limit Theorem
The mean of a standard normal distribution is always equal to ________. correct answers 0
Suppose that a random variable x has a uniform distribution with c = 2 and d =8. Find P(3 <= x
<= 5) correct answers .333
Find the area under the normal curve when P(Z > -2) correct answers .9772
Find the area under the normal curve between P(1 < z <2) correct answers .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 answers 601
Rejecting a true null hypothesis is called a ________ error. correct answers Type 1
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 answers 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 answers 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 answers 2.228 to 3.772
A confidence interval for the population mean is an interval constructed around the ________.
correct answers sample mean
When the population is normally distributed, population standard deviation σ is unknown, and
the sample size is n = 15, the confidence interval for the population mean μ is based on the z
(normal) distribution. correct answers the t distribution
The exact spread of the t distribution depends on the ________. correct answers number of
degrees of freedom
______ says that if the sample size is sufficiently large, then the sample means are approximately
normally distributed. correct answers The Central Limit Theorem
The mean of a standard normal distribution is always equal to ________. correct answers 0
