This preview shows pages 1–2. Sign up to view the full content.
Practice Test (Review)
AP Statistics:
HW#12
Name:
Directions:
Work on these sheets.
A standard normal table is attached.
Due:
Oct. 13
Part 1:
Multiple Choice
Circle the letter corresponding the best answer.
1.
A study found correlation
r
= 0.61 between the sex of a worker and his or her income.
You
conclude that
(a)
Women earn more than men on the average.
(b)
Women earn less than men on average.
(c)
An arithmetic mistake was made; this is not a possible value of
r
.
(d)
This is nonsense because
r
makes no sense here.
2.
A copy machine dealer has data on the number x of copy machines at each of 89 customer
locations and the number y of service calls in a month at each location.
Summary calculations give
x
= 8.4, s
x
= 2.1,
y
= 14.2, s
y
= 3.8, and r = 0.86.
What is the slope of the least squares
regression line of number of service calls on number of copiers?
(a)
0.86
(b)
1.56
(c)
0.48
(d)
None of these
(e)
Can’t tell from the information given
3.
In the setting of the previous problem, about what percent of the variation in the number of service
calls is explained by the linear relation between number of service calls and number of machines?
(a)
86%
(b)
93%
(c)
74%
(d)
None of these
(e)
Can’t tell from the information given
4.
If dataset A of (x,y) data has correlation coefficient
r
= 0.65, and a second dataset B has correlation
r
= –0.65, then
(a)
The points in A exhibit a stronger linear association than B.
(b)
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 01/25/2011 for the course ECON 123 taught by Professor Scruble during the Winter '10 term at California Maritime Academy.
 Winter '10
 scruble

Click to edit the document details