BUS 310 TEST 1

For a two-tailed test at 86.12% confidence, Z = a. 0.86 b. 1.96 c. 1.09 d. 1.48

1.48

For a one-tailed test (upper tail), a sample size of 18 at 95% confidence, t = a. -1.740 b. -2.12 c. 1.740 d. 2.12

1.740

The sample size needed to provide a margin of error of 2 or less with a .95 probability when the population standard deviation equals 11 is a. 10 b. 116 c. 11 d. 117

117

A sample of 225 elements from a population with a standard deviation of 75 is selected. The sample mean is 180. The 95% confidence interval for μ is a. 170.2 to 189.8 b. 175.0 to 185.0 c. 105.0 to 225.0 d. 100.0 to 200.0

170.2 to 189.8

The z value for a 97.8% confidence interval estimation is a. 2.02 b. 2.00 c. 2.29 d. 1.96

2.29

Random samples of size 36 are taken from an infinite population whose mean and standard deviation are 20 and 15, respectively. The distribution of the population is unknown. The mean and the standard error of the mean are a. 20 and 15 b. 20 and 0.417 c. 20 and 2.5 d. 36 and 15

20 and 2.5

How many simple random samples of size 3 can be selected from a population of size 7? a. 7 b. 343 c. 35 d. 21

35

We are interested in conducting a study in order to determine what percentage of voters of a state would vote for the incumbent governor. What is the minimum size sample needed to estimate the population proportion with a margin of error of 0.05 or less at 95% confidence? a. 100 b. 200 c. 385 d. 58

385

In a two-tailed hypothesis test situation, the test statistic is determined to be t = -2.692. The sample size has been 45. The p-value for this test is a. -0.005 b. -0.01 c. +0.01 d. +0.005

+0.01

In a lower one-tail hypothesis test situation, the p-value is determined to be 0.2. If the sample size for this test is 51, the t statistic has a value of a. -0.849 b. 0.849 c. -1.299 d. 1.299

-0.849

A random sample of 1000 people was taken. Four hundred fifty of the people in the sample favored Candidate A. The 95% confidence interval for the true proportion of people who favors Candidate A is a. 0.419 to 0.481 b. 1.645 to 1.96 c. 0.45 to 0.55 d. 0.40 to 0.50

0.419 to 0.481

A simple random sample of 100 observations was taken from a large population. The sample mean and the standard deviation were determined to be 80 and 12 respectively. The standard error of the mean is a. 0.12 b. 1.20 c. 8.00 d. 0.80

1.20

As the test statistic becomes larger, the p-value a. gets smaller b. stays the same, since the sample size has not been changed c. becomes larger d. becomes negative

gets smaller

An assumption made about the value of a population parameter is called a a. confidence b. significance c. conclusion d. hypothesis

hypothesis

The p-value a. is a probability b. is a distance c. measures the number of standard deviations from the mean d. is the same as the Z statistic

is a probability

To compute an interval estimate for the difference between the means of two populations, the t distribution a. is restricted to small sample situations b. is not restricted to small sample situations c. can be applied when the populations have equal means d. None of these alternatives is correct.

is not restricted to small sample situations

Which of the following is an example of nonprobabilistic sampling? a. cluster sampling b. stratified simple random sampling c. simple random sampling d. judgment sampling

judgment sampling

When the following hypotheses are being tested at a level of significance of α H0: μ 500 Ha: μ < 500 the null hypothesis will be rejected if the p-value is a. 1 - α/2 b. > α c. > α/2 d. α

less than or equal to 1 - α/2

In order to use the normal distribution for interval estimation of μ when σ is known and the sample is very small, the population a. can have any distribution b. must have a mean of at least 1 c. must have a normal distribution d. must be very large

must have a normal distribution

In computing the standard error of the mean, the finite population correction factor is used when a. n/N > 0.05 b. N/n 0.05 c. n/N 30 d. N/n > 0.05

n/N > 0.05

As the sample size increases, the margin of error a. decreases b. increases c. increases or decreases depending on the size of the mean d. stays the same

decreases

The school's newspaper reported that the proportion of students majoring in business is at least 30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypotheses is a. H0: P > 0.30 Ha: P 0.30 b. H0: P 0.30 Ha: P < 0.30 c. H0: P < 0.30 Ha: P 0.30 d. H0: P 0.30 Ha: P > 0.30

H0: P 0.30 Ha: P < 0.30

The manager of an automobile dealership is considering a new bonus plan in order to increase sales. Currently, the mean sales rate per salesperson is five automobiles per month. The correct set of hypotheses for testing the effect of the bonus plan is a. H0: μ 5 Ha: μ < 5 b. H0: μ > 5 Ha: μ 5 c. H0: μ < 5 Ha: μ 5 d. H0: μ 5 Ha: μ > 5

H0: μ 5 Ha: μ > 5

A machine is designed to fill toothpaste tubes with 5.8 ounces of toothpaste. The manufacturer does not want any underfilling or overfilling. The correct hypotheses to be tested are a. H0: μ = 5.8 Ha: μ ≠ 5.8 b. H0: μ > 5.8 Ha: μ ≤ 5.8 c. H0: μ ≥ 5.8 Ha: μ < 5.8 d. H0: μ ≠ 5.8 Ha: μ = 5.8

H0: μ = 5.8 Ha: μ ≠ 5.8

If we are interested in testing whether the mean of population 1 is significantly different from the mean of population 2, the correct null hypothesis is a. H0: μ1- μ2 = 0 b. H0: μ1- μ2 = 0 c. H0: μ1- μ2 > 0 d. H0: μ1- μ2 ≥ 0

H0: μ1- μ2 > 0

For which of the following values of P is the value of P(1 - P) maximized? a. P = 0.50 b. P = 0.90 c. P = 0.01 d. P = 0.99

P = 0.50

What type of error occurs if you fail to reject H0 when, in fact, it is not true? a. Type II b. Type I 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 tail or two tail

Type II

Cluster sampling is a. a nonprobability sampling method b. the same as convenience sampling c. a probability sampling method d. None of these alternatives is correct.

a probability sampling method

If we consider the simple random sampling process as an experiment, the sample mean is a. exactly equal to the population mean b. always zero c. a random variable d. always smaller than the population mean

a random variable

If we are interested in testing whether the mean of items in population 1 is larger than the mean of items in population 2, the a. alternative hypothesis should state μ1 - μ2 < 0 b. alternative hypothesis should state μ1 - μ2 > 0 c. null hypothesis should state μ1 - μ2 < 0 d. null hypothesis should state μ1 - μ2 > 0

alternative hypothesis should state μ1 - μ2 < 0

For a population with any distribution, the form of the sampling distribution of the sample mean is a. sometimes normal for large sample sizes b. sometimes normal for all sample sizes c. always normal for large sample sizes d. always normal for all sample sizes

always normal for large sample sizes

A sample of 25 observations is taken from an infinite population. The sampling distribution of is a. not normal since n < 30 b. approximately normal if np 5 and n(1-P) 5 c. approximately normal because is always normally distributed d. approximately normal if np > 30 and n(1-P) > 30

approximately normal if np 5 and n(1-P) 5

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

at least as small as that provided by the sample

A 95% confidence interval for a population mean is determined to be 100 to 120. If the confidence coefficient is reduced to 0.90, the interval for μ a. becomes narrower b. does not change c. becomes 0.1 d. becomes wider

becomes narrower

If two independent large samples are taken from two populations, the sampling distribution of the difference between the two sample means a. can be approximated by a Poisson distribution b. can be approximated by a normal distribution c. will have a mean of one d. will have a variance of one

can be approximated by a normal distribution

Since the sample size is always smaller than the size of the population, the sample mean a. must always be smaller than the population mean b. must be equal to the population mean c. can be smaller, larger, or equal to the population mean d. must be larger than the population mean

can be smaller, larger, or equal to the population mean

The sampling error is the a. difference between the value of the sample mean and the value of the population mean b. standard deviation multiplied by the sample size c. error caused by selecting a bad sample d. same as the standard error of the mean

error caused by selecting a bad sample

In point estimation a. data from the population is used to estimate the population parameter b. data from the sample is used to estimate the population parameter c. the mean of the population equals the mean of the sample d. data from the sample is used to estimate the sample statistic

data from the sample is used to estimate the population parameter

When developing an interval estimate for the difference between two sample means, with sample sizes of n1 and n2, a. n1 must be larger than n2 b. n1 and n2 can be of different sizes, c. n1 must be equal to n2 d. n1 must be smaller than n2

n1 and n2 can be of different sizes,

The p-value is a probability that measures the support (or lack of support) for the a. either the null or the alternative hypothesis b. sample statistic c. null hypothesis d. alternative hypothesis

null hypothesis

Parameters are a. numerical characteristics of a population b. numerical characteristics of a sample c. numerical characteristics of either a sample or a population d. the averages taken from a sample

numerical characteristics of a population

For testing the following hypothesis at 95% confidence, the null hypothesis will be rejected if Η0: μ1 - μ2 ≤ 0 Ηα: μ1 - μ2 > 0 a. p-value ≤ 0.05 b. p-value > 0.05 c. p-value ≥ 0.475 d. p-value > 0.95

p-value > 0.05

The standard error of x1- x2 is the a. variance of x1-x2 b. standard deviation of the sampling distribution of x1-x2 c. difference between the two means d. variance of the sampling distribution of x1-x2

standard deviation of the sampling distribution of x1-x2

When s is used to estimate σ, the margin of error is computed by using a. the mean of the population b. t distribution c. normal distribution d. the mean of the sample

t distribution

Whenever the population standard deviation is unknown and the population has a normal or near-normal distribution, which distribution is used in developing an interval estimation? a. alpha distribution b. z distribution c. t distribution d. standard distribution

t distribution

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. t distribution with 26 degrees of freedom b. t distribution with 25 degrees of freedom c. t distribution with 24 degrees of freedom d. normal distribution

t distribution with 24 degrees of freedom

In hypothesis testing if the null hypothesis is rejected, a. the alternative hypothesis is true b. the data must have been accumulated incorrectly c. no conclusions can be drawn from the test d. the sample size has been too small

the alternative hypothesis is true

In determining the sample size necessary to estimate a population proportion, which of the following information is not needed? a. the maximum margin of error that can be tolerated b. the confidence level required c. the mean of the population d. a preliminary estimate of the true population proportion P

the mean of the population

For the interval estimation of μ when σ is known and the sample is large, the proper distribution to use is a. the t distribution with n + 1 degrees of freedom b. the t distribution with n degrees of freedom c. the normal distribution d. the t distribution with n + 2 degrees of freedom

the normal distribution

If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error a. will not change b. will also increase from .01 to .05 c. will decrease d. will increase

will decrease