SOLUTIONS
MAT 167: Statistics
Test II
Instructor: Anthony Tanbakuchi
Spring 2009
Name:
Computer / Seat Number:
No books, notes, or friends.
Show your work.
You may use the attached
equation sheet, R, and a calculator. No other materials. If you choose to use R,
write what you typed on the test. Using any other program or having any other
documents open on the computer will constitute cheating.
You have until the end of class to finish the exam, manage your time wisely.
If something is unclear quietly come up and ask me.
If the question is legitimate I will inform the whole class.
Express all final answers to 3 significant digits. Probabilities should be given as a
decimal number unless a percent is requested. Circle final answers, ambiguous or
multiple answers will not be accepted. Show steps where appropriate.
The exam consists of 19 questions for a total of 72 points on 13 pages.
This Exam is being given under the guidelines of our institution’s
Code of Academic Ethics
. You are expected to respect those guidelines.
Points Earned:
out of 72 total points
Exam Score:

MAT 167: Statistics, Test II
SOLUTIONS p. 1 of 13
Solution:
Spring 2009 results.
>
summary( score )
Min .
1 st
Qu.
Median
Mean 3rd Qu.
Max.
17.14
50.00
69.29
67.44
82.14
97.86
>
par (mfrow = c (1 ,
2))
>
boxplot ( score ,
main = ”Boxplot
of
exam
scores ”)
>
h i s t ( score ,
main = ”Histogram
of
exam
scores ”)
20
40
60
80
100
Boxplot of exam scores
Histogram of exam scores
score
Frequency
20
40
60
80
100
0.0
1.0
2.0
3.0
1. The following is a partial list of statistical methods that we have discussed:
1. mean
2. median
3. mode
4. standard deviation
5. z-score
6. percentile
7. coefficient of variation
8. scatter plot
9. histogram
10. pareto chart
11. box plot
12. normal-quantile plot
13. confidence interval for a mean
14. confidence interval for a proportion
15. one sample mean test
16. one sample proportion test
For each situation below, which method is most applicable?
(a) (1 point) A researcher wants to estimate the mean weight loss when on the
Hot Beach
Diet
. The researcher takes a random sample of 100 people’s weight loss who used the diet.
Solution:
Construct a confidence interval for a mean.
(b) (1 point) A student needs to conduct a one-sample mean test on a sample of 25 measure-
ments. Before conducting the test, the student needs determine if the sample data appears
to have a normal distribution.
Instructor: Anthony Tanbakuchi
Points earned:
/ 2 points