QTN 561 : Week 5: DQ Questions

1

In a scatter diagram, the:

A)

dependent variable is scaled along the horizontal axis.

B)

independent variable is scaled along the vertical axis.

C)

graph shows the relationship between two variables.

D)

probabilities are plotted.

2

Correlation analysis does the following:

A)

It reports the relationship between two nominal scale variables.

B)

It evaluates the strength of the association between two interval or ratio variables.

C)

It compares two variances.

D)

It compares two means.

3

The sample coefficient of correlation:

A)

has the same sign as the slope of the regression equation.

B)

can range only from 0 to 1.00.

C)

is also called Student's t.

D)

has "n" degrees of freedom.

4

The coefficient of determination is:

A)

the square root of the correlation coefficient.

B)

between -1.00 and 1.00.

C)

inversely related to (SSE/ SS Total).

D)

based on the treatment mean square.

5

Suppose we developed the following least squares regression equation: . What can we conclude?

A)

The dependent variable increases 3.5 for each unit increase in X.

B)

The equation crosses the Y-axis at 2.1.

C)

If X = 5, then is 14.

D)

There is a significant positive relationship between the dependent and independent variables.

6

The standard error of estimate:

A)

is based on squared deviations from the regression line.

B)

may assume negative values.

C)

is in squared units of the independent variable.

D)

is the regression mean square error.

7

Which of the following is NOT a necessary condition for regression analysis?

A)

The standard deviation of each of the conditional distributions must be the same.

B)

The Y values are independent.

C)

For each X value, there is a group of Y values and these Y values are normally distributed.

D)

The slope of the regression line is positive (increasing).

8

Which of the following is not based on squared deviations from the regression line?

A)

Correlation coefficient

B)

Coefficient of determination

C)

Standard deviation

D)

Standard error of estimate

9

In an ANOVA table for simple linear regression, the degrees of freedom for the regression mean square is equal to:

A)

1.

B)

n - 1.

C)

n - 2.

D)

n

10

The term (SSR/SS total) is also called the:

A)

sum of squares due to regression.

B)

coefficient of determination.

C)

standard error of estimate.

D)

coefficient of correlation.

11

When comparing the 90% confidence interval and the 90% prediction interval for a given regression analysis, 

A)

 the confidence interval is wider than a prediction interval.

B)

  the confidence interval is narrower than a prediction interval.

C)

  there is no difference between the confidence and prediction intervals.

D)

  None of the above.

12

The hypothesis, H0: ρ = 0, is tested using a:

A)

z statistic.

B)

F statistic.

C)

t statistic with n - 1 degrees of freedom.

D)

t statistic with n - 2 degrees of freedom.

13

If the coefficient of determination is 95%, then:

A)

95% of the variation in the dependent variable is explained by the variation in the independent variable.

B)

95% of the variation in the independent variable is explained by the dependent variable.

C)

the regression equation is 95% correct.

D)

the confidence interval is a good estimate 95% of the time.