BUAL 2650 Exam 2 Chen Yan

In testing for the equality of means from two independent populations, if the hypothesis of equal population means is rejected at α = .01, it will ________ be rejected at α = .05.

Always

A new company is in the process of evaluating its customer service. The company offers two types of sales: (1) Internet sales and (2) store sales. The marketing research manager believes that the Internet sales are more than 10 percent higher than store sales. The null hypothesis would be

PInternet − Pstore ≤ .10.

(Less then or equal to .10)

A new company is in the process of evaluating its customer service. The company offers two types of sales: (1) Internet sales and (2) store sales. The marketing research manager believes that the Internet sales are more than 10 percent higher than store sales. The alternative hypothesis for this problem would be stated as

PInternet − Pstore > .10.

(Greater than .10)

If we are testing the hypothesis about the mean of a population of paired differences with samples of n1 = 10, n2 = 10, the degrees of freedom for the t statistic is ________.

9

The ________ measures the strength of the linear relationship between the dependent variable and the independent variable.

correlation coefficient

The correlation coefficient may assume any value between

−1 and 1

The following results were obtained as part of a simple regression analysis.

r2 = .9162F statistic from the F table = 3.59Calculated value of F from the ANOVA table = 81.87α = .05p-value = .000

The null hypothesis of no linear relationship between the dependent variable and the independent variable

is rejected

The coefficient of determination measures the ________ explained by the simple linear regression model.

proportion of variation

The ________ of the simple linear regression model is the value of y when the mean value of x is zero.

y-intercept

In multiple regression analysis, the explained sum of squares divided by the total sum of squares yields the __________.

R2

Which one of the following is not an assumption about the residuals in a regression model?

variance of zero

The ________ regression method is used when the response variable is a qualitative or a categorical variable.

logistic

Which of the following methods do we use to best fit the data in logistic regression?

Maximum likelihood

A soccer player takes a shot on goal 15 times and scores a goal 3 of those attempts. What are the odds of the soccer player scoring a goal?

3/12

In a simple linear regression analysis, the correlation coefficient (r) and the slope (b)________ have the same sign.

always

Estimate the value of the correlation coefficient based on the graph

Negitive R

All of the following are assumptions of the error terms in the simple linear regression model except _______.

Error terms are dependent on each other

(All should be independent)

What is the difference between F-test and t-test in multiple linear regression model? (MC)

F test

◦ The F test is used to determine whether a significant relationship exists between the dependent variable and the set of all the independent variables.

◦ The F test is referred to as the test for overall significance.

T-test

◦ If the F test shows an overall significance, the t-test is used to determine whether each of the individual independent variables is significant.

◦ A separate T-test is conducted for each of the independent variables in the model.

◦ We refer to each of these t-tests as a test for individual significance.

What is the value of SSR?

22.981

SSR+SSE=SST

?+2.568=25.544

What is the value of MSE?

.428

MSE=SSR/df(residual)

2.2568/6=.428

What is the value of F test statistic?

53.695

What is the P-value?

0.000

Find bj, and the t statistic for H0: Bj=0 on the output and report the values

B0-B1= Coefficients

s(B0)= Standard Error

t0= t stat

Calculate the 95% confidence interval for 0j

[Lower 95%,Upper 95%]

From top to bottom

A multiple regression analysis with 20 observations on each of three independent variables and the dependent variable would yield ______ and _______ degrees of freedom, respectively, for regression (explained) and error.

3, 16

In multiple regression analysis, the explained sum of squares divided by the total sum of squares yields the __________.

R2

If we are testing the significance of the independent variable X1 and we reject the null hypothesis H0: β1 = 0, we conclude that

X1 is significantly related to y

The ____________ term describes the effects on y of all factors other than the independent variables in a multiple regression model.

error

If it is desired to include marital status in a multiple regression model by using the categories single, married, separated, divorced, and widowed, what will be the effect on the model?

Four more independent variables will be included.

In multiple regression analysis, the mean square regression divided by mean square error yields the _________.

F statistic

In a simple linear regression analysis, the correlation coefficient (r) and the slope (b) ________ have the same sign.

Always

All of the following are assumptions of the error terms in the simple linear regression model except

error terms are dependent on each other

The ________ measures the strength of the linear relationship between the dependent variable and the independent variable.

correlation coefficient

In simple regression analysis, the quantity that gives the amount by which Y (dependent variable) changes for a unit change in X (independent variable) is called the

slope of the regression line

A simple regression analysis with 20 observations would yield _____

18, 19

The correlation coefficient may assume any value between

−1 and 1.

For the same set of observations on a specified dependent variable, two different independent variables were used to develop two separate simple linear regression models. A portion of the results is presented below

Based on the results given above, we can conclude that

a prediction based on Model 1 is better than a prediction based on Model 2.

The following results were obtained as part of a simple regression analysis.

r2 = .9162

F statistic from the F table = 3.59

The calculated value of F from the ANOVA table = 81.87

α = .05p-value = .000

The null hypothesis of no linear relationship between the dependent variable and the independent variable

is rejected.

In order to test the effectiveness of a drug called XZR designed to reduce cholesterol levels, the cholesterol levels of 9 heart patients are measured before they are given the drug. The same 9 patients use XZR for two continuous months. After two months of continuous use, the cholesterol levels are measured again. The comparison of cholesterol levels before versus after administering the drug is an example of testing the difference between

matched pairs from two dependent populations

In testing the difference between the means of two normally distributed populations using independent random samples with equal variances, the correct test statistic to use is the

t statistic

When testing a hypothesis about the mean of a population of paired differences in which two different observations are taken on the same units, the correct test statistic to use is ________.

t

When testing the difference between two population proportions using large independent random samples, the ________ test statistic is used.

z

If we are testing the hypothesis about the mean of a population of paired differences with samples of n1 = 10, n2 = 10, the degrees of freedom for the t statistic is ________.

9