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ECON 2843 – 010
Name
KEY
Exam 2
ID #
Fall 2006
Lab Instructor
Form A
Lab Meeting Time
Students must show all work on problems that involve calculation, even if the answer is multiple
choice.
Questions 1 – 3 refer to the following.
The dollar amounts for loans made to earthquake victims are normally distributed with a mean of
$6,000 and a standard deviation of $1,200.
1.
If we randomly sample nine of these loans, what is the probability that the sample
mean will be between $6,580 and $7,120?
(10 points)
a.
.0709
*
b.
.1394
c.
.6844
d.
.8606
e.
.9291
2.
If thirteen of these loans are randomly selected, what is the probability that the
sample variance will be less than 528,000?
(10 points)
.025
3.
Suppose that we randomly sample 64 of these loans.
What is the probability at most 41
will have a dollar amount of $6,000 or more? (10 points)
.9878
1
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View Full Document4.
Circle true or false.
As the sample size increases, the variance of the sample
mean becomes smaller.
(5 points)
True
False
5.
Circle true or false.
As the sample size increases, the distribution of the sample mean
approaches the Normal distribution.
(5 points)
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 Spring '08
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