WorksheetsPSCP S2 Practice Exam #5
Total questions: 10
Worksheet time: 5mins
A correlation cannot have the value
0.4
-0.75
1.5
0.0
0.99
Which correlation indicates a strong positive straight line relationship?
0.4
-0.75
1.5
0.0
0.99
If the least squares regression line for predicting y from x is y = 500 - 20x, what is the predicted value of y when x = 10?
300
500
200
700
20
To display the relationship between per capita wine consumption and heart disease death rates per 100,000 people, in each of 29 countries, a good choice of a graph would be a
angiogram
boxplot
histogram
line graph
scatterplot
Which of these statements is true of the correlation r?
(a) r always takes values 0 or greater than 0.
(b) r always takes values between -1 and 1.
(c) r describes only straight line relationships.
(d) Both (a) and (c).
(e) Both (b) and (c).
The least-squares regression line for x = SAT and y = GPA is:
y = 137.0x
y = 239.4 + 137.0x
y = 137.0 + 239.4x
y = –0.103 + 0.005x
y = 0.005 – 0.103x
The correlation coefficient r between GPA and SAT is:
-0.32
1.2
0.68
0.83
1
Suppose we wanted to predict the future GPA of a sixth incoming student who has an SAT score of 788. Our best prediction on the basis of the given data would be
3.70
3.72
3.75
3.79
3.84
The equation of the least-squares regression line of crime (y) on enrollment (x) is
y = 21.8x – 112.6
y = –112.6x + 21.8
y = 112.6x – 21.8
y = 0.04x + 7.0
y = 7.0x + 0.04
If the point (26, 601) were removed from the data, how would the slope of the regression line change?
The slope of the new line would be steeper than the original line.
The slope of the new line would be less steep than the original line.
The slope would change from positive to negative.
The slope would change from negative to positive.
The slope would remain the same.
