Bus220 Midterm Review Geng

The p-value a)can be any positive value b) can be any negative value by the sample c) must be a number between -1 and 0 d) must be a number between 0 and 1.

must be a number between 0 and 1.

For a lower tail test, the p-value is the probability of obtaining a value for the test statistic at least as a)small as that provided by the sample b)large as that provided by the sample c)small as that provided by the population d)large as that provided by the population

small as that provided by the sample

. From a population that is normally distributed, a sample of 25 elements is selected and the standard deviation of the sample is computed. For the interval estimation of μ, the proper distribution to use is the a.Normal distribution b.t distribution with 25 degrees of freedom c.t distribution with 24 degrees of freedom d.t distribution with 26 degrees of freedom

t distribution with 24 degrees of freedom

. For the interval estimation of μ when σ is unknown and the sample is large, the proper distribution to use is the a. normal distribution b. t distribution with n degrees of freedom c. t distribution with n+1 degrees of freedom d. t distribution with n-1 degrees of freedom

t distribution with n-1 degrees of freedom

The probability of committing a Type I error when the null hypothesis is true as an equality is a) the confidence level b) β c) greater than 1 d) the level of significance α

the level of significance α

. For a lower tail test, the test statistic z is determined to be negative. The p-value for this test is A) 0. B) 0.5 C) <0.5 D) >0.5 E) 1

<0.5

Whenever the population has a normal probability distribution, the sampling distribution of is a normal probability distribution for a.Large sample size b.Small sample size c.Any sample size d.Sample size of 30 or greater

Any sample size

Which of the following is true about the student's t distribution? a. It has less area in the tails and more in the center than does the normal distribution. b. It is used to construct confidence intervals for the population mean when the population standard deviation is known. c. Its degree of freedom is n. d. As the number of degrees of freedom increases, the t distribution approaches the normal distribution.

As the number of degrees of freedom increases, the t distribution approaches the normal distribution.

Using an α = .04, a confidence interval for a population proportion is determined to be .65 to .75. For the same data, if α is decreased, the confidence interval for the population proportion a)Becomes narrower b)Becomes wider c)remains the same d)Has a zero margin of error

Becomes wider

A juice drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of drink on an average. Any overfilling or underfilling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjusted, the correct set of hypotheses is a. Ho: µ=12 Ha: µ≠12 b. Ho: µ≤12 Ha: µ>12 c. Ho: µ≥12 Ha: µ<12 d. Ho: µ≠12 Ha: µ=12

Ho: µ=12 Ha: µ≠12

. As the sample size increases, the variability among the sample means a.Increases b.Decreases c.Remains the same d.depends upon the specific population being sampled.

Decreases

. In the past, 75% of the tourists who visited Chattanooga went to see Rock City. The management of Rock City recently undertook an extensive promotional campaign. They are interested in determining whether the promotional campaign actually increased the proportion of tourists visiting Rock City. The correct set of hypotheses is a.Ho: p>0.75 Ha: p≤ 0.75 b.Ho: p<0.75 Ha: p≥ 0.75 c.Ho: p≥0.75 Ha: p≤ 0.75 d.Ho: p≤0.75 Ha: p> 0.75

Ho: p≤0.75 Ha: p> 0.75

The average monthly rent for one-bedroom apartments in Chattanooga has been $800. Because of the downturn in the real estate market, it is believed that there has been a decrease in the average rental. The correct hypotheses to be tested are a. Ho: µ=800 Ha: µ≠800 b. Ho: µ≥800 Ha: µ<800 c. Ho: µ>800 Ha: µ≤800 d. Ho: µ<800 Ha: µ≥800

Ho: µ≥800 Ha: µ<800

. If the null hypothesis is rejected at the 5% level of significance (p-value<5%), it _____ at the 1% level. a.Will always be rejected b.Will always not be rejected c.Will never be tested d.May be rejected or not rejected

May be rejected or not rejected

Random samples of size 2 are taken from an infinite population with a mean of 36 and a standard deviation of 8. Which of the following best describes the form of the sampling distribution of the sample mean for this situation? a.Approximately normal because the sample size is small relative to the population size b.Approximately normal because of the central limit theorem c.Exactly normal d.None of the above

None of the above

The population is binomially distributed. As the sample size becomes larger, the sampling distribution of the sample mean approaches a _____ distribution. a.Binomial b.Poisson c.Normal d.Chi-square

Normal

If a hypothesis test leads to the rejection of the null hypothesis, a _____ have been committed. a.Type II error must b.Type II error may c.Type I error must d.Type I error may

Type I error may

What type of error occurs if you accept Ho when, in fact, it is not true? a.Type I b.Type II c.either type I or Type II, depending on the level of significance d.Either type I or Type II, depending on whether the test is one-tailed or two-tailed.

Type II

The p-value is a.the same as the z statistic. b.a sample statistic. c.a distance d. a probability

a probability

When the level of confidence increases, the margin of error a.stays the same b.becomes smaller c.becomes larger d.Becomes smaller or larger, depending on the sample mean

becomes larger