Download The number of hours that each of a group of

Name: _____________________________
PRACTICE TEST 1
Complete questions 1-24 by circling the correct answer.
Complete questions 25-29 by providing answers and showing all appropriate work.
1. Which statistical measure is not strongly affected by a few outliers in the data?
a) mean
b) median
c) standard deviation
d) correlation
Use the information below for the following two (2) questions.
The scores for a statistics test have a bell-shaped distribution. 95% of all the scores were between 72 and 88.
2. The mean for this statistics test was
a) 72.
b) 76.
c) 80.
d) 88.
3. The standard deviation of the statistics test scores was
a) 8.
b) 4.
c) 2.
d) 5.
Use the following set of data for Questions 4-6:
An SRS of 1000 words was taken from articles in Popular Science magazine, and the frequency distribution for
the number of words having 1 to 15 letters was constructed. (Make sure that you understand what the frequency
distribution is saying. There are 1000 words in your list of interest, 36 have 1 letter, 148 have 2 letters, etc.)
Word
Length
Freq.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
36
148
187
160
125
82
81
59
44
36
21
9
6
4
2
4. What is the maximum of these 1000 word lengths?
a) 3
b) 187
c) 2
d) 15
5. About what percentage of these words are longer than 7 letters?
a) 18.1%
b) 81.9%
c) 50%
d) 73.8%
6. Which is the preferred measure of “center” here and why?
a) the mean because it uses all of the data
b) the median because the distribution of the data is skewed
c) the mean because the distribution of the data is skewed
d) the standard deviation because it measures more than just the center
7. Scores on a personnel examination at the Anderson Electronics Company have a bell-shaped distribution
with a mean of 73 and a standard deviation of 5. Therefore, approximately half of all personnel examination
scores are higher than
a) 73.
b) 78.
c) 68.
d) 83.
8. Based on previous clients, a marriage counselor concludes that the majority of marriages that begin with
cohabitation before marriage will result in divorce. Does this statement describe inferential statistics or
descriptive statistics?
a) descriptive statistics
b) inferential statistics
Use the following data to answer Questions 9-12:
The number of hours that each of a group of students studied for an exam were as follows:
1
1.5
2
3
4
4.5
5
6
6.5
9. What is the median number of study hours?
a) 4
b) 4.5
c) 5
d) 5.5
10. What is the mean number of study hours?
a) 5
b) 5.19
c) 5.5
d) 6
11. What is the third quartile of the number of study hours?
a) 2.5
b) 6.5
c) 7
d) 7.25
7
7.5
8.5
11
12. Which of your results in the previous three questions would change if the 11 hours were 22 hours instead?
a) All of them would change.
b) The mean and the third quartile would change.
c) The median would change.
d) The mean would change.
13. To illustrate a talk you are giving, you want to make a graph to compare the percentages of adults in several
countries who have finished college. You should make a
a) histogram
b) line graph
c) pie chart
d) bar graph
14. Below is a boxplot of the salaries of Renata College Alumni who graduated two years ago. About what
percentage of these graduates make more than $36,900?
a) 25%
b) 10%
c) 50%
d) 75%
15. You wish to show the change over time in the percent of children living in households with incomes below
the poverty level set by the government from 1965 to 2000. What type of graph would be the best to use?
a) histogram
b) line graph
c) pie chart
d) pareto chart
16. To display the distribution of the lengths (in inches) of a sample of brook trout, you should use a
a) histogram
b) line graph
c) pie chart
d) bar graph
17. If a distribution is skewed to the left, then which is smaller, the mean or the median?
a) mean
b) median
18. Classify the colors of automobiles on a used car lot as qualitative data or quantitative data.
a) qualitative
b) quantitative
19. Identify the level of measurement for data that are the ages of students in a statistic class.
a) nominal
b) ordinal
c) interval
d) ratio
20. Identify the level of measurement for data that are the years the summer Olympics were held in the United
States.
a) nominal
b) ordinal
c) interval
d) ratio
21. A researcher for an airline interviews all of the passengers on five randomly selected flights. What sampling
technique is used?
a) cluster
b) random
c) convenience
d) stratified
e) systematic
22. A community college student interviews students in her statistics class to determine who owns a car. What
sampling technique is used?
a) cluster
b) random
c) convenience
d) stratified
e) systematic
23. The birth weights for twins have a bell-shaped distribution with a mean of 2353 grams and a standard
deviation of 647 grams. Use z-scores to determine which birth weight is most unusual.
a) 3,600g
b) 1200g
c) 2,000g
d) 2353g
24. For the stem-and-leaf plot below, find the range of the data set.
1 | 45
2|666789
3|77788999
4|01123445
4|6667889
5|00
a) 40
b) 36
c) 26
d) 14
The remaining questions are short answer questions. You must show all of your work to receive full credit.
25. A recent survey by the alumni of a major university indicated that the average salary of 10,000 of its
300,000 graduates was $125,000.
a) Identify the population and the sample.
b) Does $125,000 describe a parameter or a statistic? Explain your reasoning.
Use the following histogram to answer Questions 26-28.
Bowling Scores
14
10
8
6
4
# of bowlers
12
2
0
280
260
240
220
200
180
160
140
120
Scores
26. What is the class width?
27. Which class represents the mode of the data set? (Give the upper and lower bounds of the class.)
28. Which is greater, the mean or the median?
29. The mean price of new homes from a sample of houses is $155,000 with a standard deviation of $15,000.
The data set has a bell-shaped distribution. Between what two prices do 99.7% of the houses fall?