QMB3200 Ch, 9, 10, & 14

d. 1.16

A one-tailed test (upper tail) at a .123 level of significance has a z value of _____. a. 1.645 b. 1.54 c. 1.96 d. 1.16

c. a true null hypothesis is rejected

A Type I error is committed when _____. a. sample data contradict the null hypothesis b. a true alternative hypothesis is not accepted c. a true null hypothesis is rejected d. the critical value is greater than the value of the test statistic

b. matched

A company wants to identify which of two production methods has the smaller completion time. One sample of workers is randomly selected and each worker first uses one method and then uses the other method. The sampling procedure being used to collect completion time data is based on _____ samples. a. independent b. matched c. cross d. pooled

c. -1.53

A one-tailed test (lower tail) at a .063 level of significance has a z value of _____. a. -1.86 b. -1.645 c. -1.53 d. -1.96

a. in one tail of the sampling distribution

A one-tailed test is a hypothesis test in which rejection region is _____. a. in one tail of the sampling distribution b. only in the lower tail of the sampling distribution c. in both tails of the sampling distribution d. only in the upper tail of the sampling distribution

d. $1 in price is associated with a decrease of $8,000 in sales

A regression analysis between sales (in $1000s) and price (in dollars) resulted in the following equation:ŷ = 50,000 − 8xThe above equation implies that an increase of _____. a. $8 in price is associated with an increase of $8,000 in sales b. $1 in price is associated with a decrease of $8 in sales c. $1 in price is associated with a decrease of $42,000 in sales d. $1 in price is associated with a decrease of $8,000 in sales

c. -1.79 and 1.79

A two-tailed test at a 0.0735 level of significance has z values of _____. a. -1.45 and 1.45 b. -1.05 and 1.05 c. -1.79 and 1.79 d. -0.90 and 0.90

a. the null hypothesis should be rejected and the alternative accepted

A two-tailed test yields a p-value of .025. At the 8% level of significance a. the null hypothesis should be rejected and the alternative accepted b. the null hypothesis should be rejected and the alternative rejected c. the null hypothesis should not be rejected and the alternative accepted d. the null hypothesis should not be rejected and the alternative not accepted

c. t = 3.20

An economist is attempting to estimate the amount of unsecured debt a household has (measured in thousands of dollars) from the household's combined monthly gross income (measured in hundreds of dollars). The following information was gathered from n = 12 observations: y = 2.00 + 0.08x SSE = 700 SST = 1,000 sb1 = 0.025 Suppose we wish to test the hypothesis H0: β1 = 0 vs. HA: β1 ≠ 0. What would be the value of our t test statistic? Select one: a. t = 1.16 b. t = 2.25 c. t = 3.20 d. t = 4.20

c. $4,400

An economist is attempting to estimate the amount of unsecured debt a household has (measured in thousands of dollars) from the household's combined monthly gross income (measured in hundreds of dollars). The following information was gathered from n = 12 observations: y = 2.00 + 0.08x SSE = 700 SST = 1,000 sb1 = 0.025 What is the predicted unsecured debt level for a household that has a combined monthly gross income of $3,000? a. $2,400 b. $2,800 c. $4,400 d. $5,600

c. F = 4.29

An economist is attempting to estimate the amount of unsecured debt a household has (measured in thousands of dollars) from the household's combined monthly gross income (measured in hundreds of dollars). The following information was gathered from n = 12 observations: y = 2.00 + 0.08x SSE = 700 SST = 1,000 sb1 = 0.025 What is the value of the F test statistic? a. F = 1.68 b. F = 2.25 c. F = 4.29 d. F = 8.04

c. (III)

An economist is attempting to estimate the amount of unsecured debt a household has (measured in thousands of dollars) from the household's combined monthly gross income (measured in hundreds of dollars). The following information was gathered from n = 12 observations: y = 2.00 + 0.08x SSE = 700 SST = 1,000 sb1 = 0.025 Which of the following correctly represent's the economist's simple linear regression model? (I) y = 2.00 + 0.08x (II) y = b0 + b1x (III) y = β0 + β1x + ε (IV) E(y) = β0 + β1x a. (I) b. (II) c. (III) d. (IV)

d. alternative hypothesis

As a general guideline, the research hypothesis should be stated as the _____. a. tentative assumption b. hypothesis the researcher wants to disprove c. null hypothesis d. alternative hypothesis

d. The correct degrees of freedom cannot be calculated without being given the sample standard deviations.

Independent simple random samples are selected to test the difference between the means of two populations whose standard deviations are not known. We are unwilling to assume that the population variances are equal. The sample sizes are n1 = 20 and n2 = 30. The correct distribution to use is the t distribution with how many degrees of freedom? a. 30 b. 20 c. 48 d. The correct degrees of freedom cannot be calculated without being given the sample standard deviations.

d. -1.383

For a one-tailed test (lower tail) with a sample size of 10 and a .10 level of significance the t value is _____. a. -1.372 b. 1.383 c. -2.821 d. -1.383

d. 1.328

For a two-tailed test with a sample size of 20 and a .20 level of significance, the t value is _____. a. 1.325 b. 2.539 c. 2.528 d. 1.328

a. also not be rejected at the 1% level

If a hypothesis is not rejected at a 5% level of significance, it will _____. a. also not be rejected at the 1% level b. sometimes be rejected at the 1% level c. always be rejected at the 1% level d. may be rejected or not rejected at the 1% level.

b. may be rejected or not rejected at the 1% level

If a hypothesis is rejected at a 5% level of significance, it _____. a. will always be rejected at the 1% level b. may be rejected or not rejected at the 1% level c. will always be accepted at the 1% level d. will never be tested at the 1% level

b. Type I error may have been committed

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

c. p1 - p2 ≤ 0

If the alternative hypothesis is that proportion of items in population 1 is larger than the proportion of items in population 2, then the null hypothesis should be _____. a. p1 - p2 = 0 b. p1 - p2 > 0 c. p1 - p2 ≤ 0 d. p1 - p2 < 0

d. SSR = SST

If the coefficient of determination is 1, then a. SSE = SST b. SSR - SSE = SST c. SSR = SSE d. SSR = SST

d. is either -1 or +1

If the coefficient of determination is 1, then the correlation a. is definitely -1 b. is definitely +1 c. is definitely 0 d. is either -1 or +1

b. 0.25

In a regression setting, if SSR = 200 and SST = 800, then what is the coefficient of determination? a. 0.10 b. 0.25 c. 0.50 d. 0.75

c. there is a positive correlation between x and y

In a simple regression analysis (where y is a dependent and x an independent variable), if the slope is positive, then it must be true that _____. a. the y-intercept is 0 b. there is a negative correlation between x and y c. there is a positive correlation between x and y d. there is no correlation between x and y

b. less than or equal to α

In a two-tailed hypothesis test, the null hypothesis should be rejected if the p-value is _____. a. less than or equal to 2α b. less than or equal to α c. greater than or equal to 2α d. greater than or equal to α

a. the null hypothesis

In hypothesis testing, the hypothesis tentatively assumed to be true is _____. a. the null hypothesis b. either the null or the alternative hypothesis, depending on the sample size. c. the alternative hypothesis d. always proven to be true

a. is the probability of getting sample data at least as extreme as ours, assuming H0 is true

In hypothesis testing, the p-value a. is the probability of getting sample data at least as extreme as ours, assuming H0 is true b. is the probability of getting sample data at least as extreme as ours, assuming HA is true c. is the probability that H0 is false d. is the probability that H0 is true

c. wider than

In regression, a prediction interval for y at a particular value of x will be __________________ a confidence interval for E(y) for the same value of x. a. narrower than b. the same width as c. wider than

c. the level of significance

In the hypothesis testing procedure, α is _____. a. the confidence level b. 1 − level of significance c. the level of significance d. the critical value

a. t

Independent simple random samples are selected to test the difference between the means of two populations whose variances are not known. The sample sizes are n1 = 32 and n2 = 40. The correct distribution to use is the _____ distribution. a. t b. uniform c. normal d. binomial

c. $42.00

The equation which predicts the price of a used car (y or dependent variable) from its weight, in pounds (x or independent variable) is given by the equation y = 90 + 1.40x. If a car manufacturer adds a new feature that increases the weight of a car by 30 pounds, by how much should its price increase? a. $1.40 b. $132.00 c. $42.00 d. $90.00

a. a Type I error

The error of rejecting a true null hypothesis is _____. a. a Type I error b. committed when the sample size is too small c. a Type II error d. committed when not enough information is available

b. min Σ(yi - ŷi)2

The least squares criterion is _____. a. min Σ(yi - ȳ)2 b. min Σ(yi - ŷi)2 c. min (Σyi - ŷi)2 d. min Σ(xi - yi)2

a. α

The level of significance is symbolized by _____. a. α b. β c. ρ d. σ

d. maximum allowable probability of a Type I error

The level of significance is the _____. a. maximum allowable probability of a Type II error b. same as the confidence coefficient c. same as the p-value d. maximum allowable probability of a Type I error

c. the level of significance

The probability that the interval estimation procedure will generate an interval that DOES NOT contain the population parameter a. degree of association b. is the precise value of the population statistic c. the level of significance d. the type II error rate

a. coefficient of determination

The proportion of the variation in the dependent variable y that is explained by the estimated regression equation is measured by the _____. a. coefficient of determination b. standard error of the estimate c. confidence interval estimate d. correlation coefficient

a. standard deviation of the sampling distribution of x̄1 - x̄2

The standard error of x̄1 - x̄2 is the _____. a. standard deviation of the sampling distribution of x̄1 - x̄2 b. variance of the sampling distribution of x̄1 - x̄2 c. difference between the two means d. variance of x̄1 - x̄2

c. the test statistic

The value computed from sample data that tells us how many standard errors above or below the hypothesized value our data fell is known as a. the critical value b. the level of significance c. the test statistic d. the type I error

c. the critical value

The value to which we compare our test statistic to determine if it fell in the rejection region is known as a. the alpha level b. the critical value c. the p-value d. the significance level

a. p-value and critical value

Two approaches to drawing a conclusion in a hypothesis test are _____. a. p-value and critical value b. one-tailed and two-tailed c. null and alternative d. Type I and Type II

d. There is not enough information to answer this question

Two independent populations were selected. The following information was gathered: n1 = 24 n2 = 28 Assume we do not believe the variances are equal. In performing a two sample t test on the difference in means, how many degrees of freedom should we use? a. 23 b. 27 c. 50 d. There is not enough information to answer this question

c. 37 degrees of freedom

Two independent random samples were taken from populations whose standard deviations are unknown. The first sample had n = 15 observations and a sample standard deviation of s = 60. The second sample had n = 25 observations and a sample standard deviation of s = 90. We are not willing to assume that the variances are the same in the populations. How many degrees of freedom should we use to run a hypothesis test of two independent means? Remember to round your answer DOWN to the nearest whole number. a. 24 degrees of freedom b. 32 degrees of freedom c. 37 degrees of freedom d. 45 degrees of freedom

a. p1 - p2 < 0

What is the appropriate alternative hypothesis for a manufacturer who claims the proportion of defective items for his morning shift (group 1) is significantly lower than the proportion of defective items for his late shift (group 2)? a. p1 - p2 < 0 b. p1 - p2 = 0 c. p1 - p2 ≠ 0 d. p1 - p2 > 0

b. n1 and n2 can be of different sizes

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

a. matched samples

When each data value in one sample is matched with a corresponding data value in another sample, the samples are known as _____. a. matched samples b. dependent samples c. corresponding samples d. independent samples

b. independent samples

When samples are selected in such a fashion that the outcomes of observations in one sample have no bearing upon the outcomes of the observations in another sample are known as a dependent samples b. independent samples c. matched samples d. paired samples

c. p-value ≤ α

When the p-value is used for hypothesis testing, the null hypothesis is rejected if _____. a. α < p-value b. p-value > α c. p-value ≤ α d. p-value = z

a. less than or equal to the test statistic

When the rejection region is in the lower tail of the sampling distribution, the p-value is the area under the curve _____. a. less than or equal to the test statistic b. greater than or equal to the test statistic c. less than or equal to the critical value d. greater than or equal to the critical value

c. H0: μ < 0

Which of the following hypotheses is not a valid null hypothesis? a. H0: μ ≥ 0 b. H0: μ ≤ 0 c. H0: μ < 0 d. H0: μ = 0

b. H0: μ < μ0 and Ha: μ ≥ μ0

Which of the following is an improper form of the null and alternative hypotheses? a. H0: μ = μ0 and Ha: μ ≠ μ0 b. H0: μ < μ0 and Ha: μ ≥ μ0 c. H0: μ ≤ μ0 and Ha: μ > μ0 d. H0: μ ≥ μ0 and Ha: μ < μ0

d. SST = SSR + SSE

Which of the following is correct? a. SST = (SSR)2 b. SSR = SSE + SST c. SSE = SSR + SST d. SST = SSR + SSE

b. H0: μ ≥ 10.0% Ha: μ < 10.0%

Your investment executive claims that the average yearly rate of return on the stocks she recommends is at least 10.0%. You plan on taking a sample to test her claim. The correct set of hypotheses is _____. a. H0: μ ≤ 10.0% Ha: μ > 10.0% b. H0: μ ≥ 10.0% Ha: μ < 10.0% c. H0: μ > 10.0% Ha: μ ≤ 10.0% d. H0: μ < 10.0% Ha: μ ≥ 10.0%