Multiple Choice
Using the frequency table below, find how many students received a score of 70 or better on a mathematics test.
Score Interval
Frequency
50 – 59
2
60 – 69
5
70 – 79
5
80 – 89
7
90 – 99
2
A. 19
B. 12
C. 17
D. 14
C. 17
Researchers at Jackson Hospital asked 40 randomly selected patients about their sleep habits. Sixteen reported sleeping 8 hours or more each night. If there are 700 patients in the hospital, estimate the number of patients who sleep 8 hours or more each night.
A. 140
B. 160
C. 180
D. 280
B. 160
To estimate the number of patients who sleep 8 hours or more each night, we can use proportion:
16/40 = x/700
Solving for x:
x = (16/40) * 700
x = 280/2 = 140
We can estimate that about 140 patients out of the 700 in the hospital sleep 8 hours or more each night.
A newspaper reporter wants to know how popular the hobby of bird watching is in the city. He asked people at the local bird refuge if they watched birds as a hobby. Which of the following best explains whether the reporter's data is valid or not?
A. The data is valid for the entire city because the bird refuge is located in the city.
B. The data is not valid for the entire city because people can have more than one hobby.
C. The data is not valid for the entire city because bird watchers are more likely to visit a bird refuge.
D. The data is valid for the entire city because a bird refuge is a good place to find people who like to watch birds.
C. The data is not valid for the entire city because bird watchers are more likely to visit a bird refuge.
The data collected by the reporter may not be valid for the entire city because people who visit a bird refuge are more likely to be interested in bird watching as a hobby than the general population. Furthermore, people who are not interested in bird watching would have no reason to visit a bird refuge. As a result, the sample may not be representative of the population as a whole, and the data may be biased. Therefore, option C is the best explanation.
Which of the following types of information is suited for display on a double line graph?
A. average wages paid to men and to women over 5 years
B. average heights of basketball players in five schools
C. average ages of people entering the pubic library in five locations
D. average prices of two car models at five dealerships
D. Average prices of two car models at five dealerships.
Double line graphs are typically used to show the relationship between two variables over time or some other shared interval. For example, a double line graph could be used to show how the average price of two car models changes over time. Option D is the only answer that includes data that can be compared on a shared interval (i.e. the same set of dealerships).
Option A is better suited for a side-by-side bar graph, whereas Option B and Option C may be better suited for a grouped bar graph.
The stem and leaf plot below shows the number of points scored in each basketball game a team played during a season. In how many games were more than 40 points scored?
Stem
Leaf
6
1 6 7
5
2 2 8
4
4 5 8 9
3
0 2 6 6 6
2
0 8
A. 4
B. 6
C. 7
D. 10
C. 7
To find out in how many games were more than 40 points scored, we need to look at the numbers in the stem and leaf plot that are greater than 4 (since the stem for 40 is 4).
We can see from the plot that there are 3 games with a score of 51, 1 game with a score of 52, 1 game with a score of 54, and 2 games with a score of 69.
Therefore, the answer is 3 + 1 + 1 + 2 = 7.
The stem-and-leaf plot shows the height, in inches, of the players on two different basketball teams. How many players on each team are less than 70 inches tall?
Heights of Players
In inches
Austin College Barton College
Leaf
Stem
Leaf
6 7 8 8 9
6
4 6 8
1 1 2 6
7
1 1 1 3 4 5
1
8
2
A. Austin College, 4; Barton College, 6
B. Austin College, 5; Barton College, 7
C. Austin College, 5; Barton College, 3
D. Austin College, 9; Barton College, 9