Name: __________________________________________ Period: _____ Date: ___________
Chapter 1 Test Review
1. The histogram shows the number of major hurricanes that reached the East Coast of the United States from 1944 to
2000. Describe the distribution.
15
10
5
0
0
1
2
3
4
5
6
7
Hurri c a ne s
2. Hallux abducto valgus (call it HAV) is a deformation of the big toe that is not common in youth and often requires
surgery. Doctors used X-rays to measure the angle (in degrees) of deformity in 38 consecutive patients under the age
of 21 who came to a medical center for surgery to correct HAV. The angle is a measure of the seriousness of the
deformity. Here are the data.
28 32 25 34 38 26 25 18 30 26 28 13 20
21 17 16 21 23 14 32 25 21 22 20 18 26
16 30 30 20 50 25 26 28 31 38 32 21
Make a stemplot and give a numerical description of this distribution (what do the stems and leaves represent?). Are
there any outliers? Write a brief discussion of the shape, center, and spread of the angle of deformity among young
patients needing surgery for this condition.
3.
I have a data set consisting of 33 whole number observations. Its five-number summary is (16, 20, 22, 30, 46).
a. What is the spread of the data?
b. Tell what the five numbers in the five-number summary represent. Be specific.
c. How many observations are strictly less than 22?
d. Is it possible that there is no observation equal to 22? Explain briefly.
e. How many observations are strictly less than 20?
f.
Is it possible that there is no observation equal to 20? Explain briefly.
g. Test for outliers. Are there any outliers?
h. Construct a modified boxplot.
i.
Approximately where is the mean? Briefly explain your reasoning.
4. Write the letter of the histogram next to the appropriate variable number in the table below. Explain briefly how
you made your choice.
Variable Mean Median St.Dev.
1
50
50
10
2
50
50
15
3
53
50
10
4
53
50
20
5
47
50
10
6
50
50
5
5. Label the following variables as categorical or quantitative:
a.
b.
c.
d.
e.
whether or not a light bulb works
number of rings until a person answers the phone
time it takes a computer to download a particular applet
hair color of children entering 4th grade
names of colleges most applied to in Texas
6. A random sample of records of resales of homes from Feb 15 to Apr 30, 1993 from the files maintained by the
Albuquerque Board of Realtors was collected. The amount of tax paid annually for 19 houses in a particular part of
town is as follows:
1639, 1688, 1693, 1635, 1632,
1704, 1660, 1633, 1694, 1667,
1661, 1610, 1691, 1684, 1682
1634, 1665, 1650, 1630
Construct the stemplot.
Describe the distribution.
7. Given the stemplot, determine if the data is skewed left or right or is relatively symmetrical. Also, indicate the
position of the mean, relative to the median (higher, lower, or same).
9|3571
8|241153378
7|19002
6|234
5|0
4|27
A large regional real estate company keeps records of home sales for each of its sales agents. Each month, the company
publishes the sales volume for each agent. Monthly sales volume is defined as the total sales price of all homes sold by
the agent during a month. The figure below displays the cumulative relative frequency plot of the most recent monthly
sales volume (in hundreds of thousands of dollars) for these agents.
a. In the context of this question, explain what information is conveyed by the circled point.
b. What proportion of sales agents achieved monthly sales volumes between $700,000 and $800,000?
c. For values between 10 and 11 on the horizontal axis, the cumulative relative frequency plot is flat. In
context of this question, explain what this means.
d. A bonus is to be given to 20 percent of the sales agents. Those who achieved the highest monthly sales
volume during the preceding month will receive a bonus. What is the minimum monthly sales volume an
agent must have achieved to qualify for the bonus?