Statistics Final
1. A sales manager for an advertising agency believes there is a relationship between the number
of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis
shows the following results.
Coefficients
Standard Error t-
Stat
p-value
Intercept
12.201
6.560
1.860
0.100
Number of contacts 2.195
0.176
12.505
0.000
What is the standard error of the slope?: The standard error of the slope is listed as the standard
error for the independent variable "number of contacts," or 0.176.
2. Using the following information:
Coefficients
Intercept
12.8094
Independent variable
2.1794
ANOVA
df
SS
MS
F
Regression 1
12,323.62
12,323.62
90.0481
Residual 8
, Statistics Final
1,184.782
136.8553
Total
9
13,508.4
What is the coefficient of determination? Round the percentage to one decimal point.: The
coefficient of determination is the explained variation as a percent of the total variation, or from the
ANOVA table R2 = (SSRegression ÷ SSTotal) = 12,323.62
÷ 13,508.4 = 0.9123, or 91.2%.
3. The regression equation is v = 29.29 0.96X, the sample size is 8, and the standard error
of the slope is 0.22. What is the test statistic to test the significance of the slope?: t = 4.364 ;
-0.96-0/0.22
4. If the coefficient of determination is 0.94, what can we say about the rela- tionship between
two variables?: Ninety-four percent of the total variation of the dependent variable is explained by the
independent variable.
5. In regression, the difference between the confidence interval and prediction interval formulas
is .: the addition of 1 to the quantity under the radical sign
6. An instructor is wondering if students who spend more time taking their final exam do
better than those who take less time. The following data is gathered.
Minutes 57,47,36,83,86,117,87,62,87,86,68,106,95,72,95
Score 96,92,92,77,96,96,81,85,88,96,70,81,77,74,77
What is the slope of the regressed line?: The slope is the coefficient for the independent
variable "number of minutes," is 0.053.
7. Using the following information:
Coefficients
Intercept
12.8094
Independent variable
2.1794
ANOVA
df
SS
MS
F
Regression 1
1. A sales manager for an advertising agency believes there is a relationship between the number
of contacts that a salesperson makes and the amount of sales dollars earned. A regression analysis
shows the following results.
Coefficients
Standard Error t-
Stat
p-value
Intercept
12.201
6.560
1.860
0.100
Number of contacts 2.195
0.176
12.505
0.000
What is the standard error of the slope?: The standard error of the slope is listed as the standard
error for the independent variable "number of contacts," or 0.176.
2. Using the following information:
Coefficients
Intercept
12.8094
Independent variable
2.1794
ANOVA
df
SS
MS
F
Regression 1
12,323.62
12,323.62
90.0481
Residual 8
, Statistics Final
1,184.782
136.8553
Total
9
13,508.4
What is the coefficient of determination? Round the percentage to one decimal point.: The
coefficient of determination is the explained variation as a percent of the total variation, or from the
ANOVA table R2 = (SSRegression ÷ SSTotal) = 12,323.62
÷ 13,508.4 = 0.9123, or 91.2%.
3. The regression equation is v = 29.29 0.96X, the sample size is 8, and the standard error
of the slope is 0.22. What is the test statistic to test the significance of the slope?: t = 4.364 ;
-0.96-0/0.22
4. If the coefficient of determination is 0.94, what can we say about the rela- tionship between
two variables?: Ninety-four percent of the total variation of the dependent variable is explained by the
independent variable.
5. In regression, the difference between the confidence interval and prediction interval formulas
is .: the addition of 1 to the quantity under the radical sign
6. An instructor is wondering if students who spend more time taking their final exam do
better than those who take less time. The following data is gathered.
Minutes 57,47,36,83,86,117,87,62,87,86,68,106,95,72,95
Score 96,92,92,77,96,96,81,85,88,96,70,81,77,74,77
What is the slope of the regressed line?: The slope is the coefficient for the independent
variable "number of minutes," is 0.053.
7. Using the following information:
Coefficients
Intercept
12.8094
Independent variable
2.1794
ANOVA
df
SS
MS
F
Regression 1
