1.
Find the median in the set of data 23, 13, 18, 29, 32, 25.
Correct Answer
B. 24
Explanation
The median is the middle value in a set of data when the data is arranged in ascending or descending order. In this case, the data set is already in ascending order: 13, 18, 23, 25, 29, 32. There are 6 numbers in the set, so the middle value would be the 3rd number, which is 23. However, since there is an even number of values, the median is the average of the two middle values, which are 23 and 25. The average of 23 and 25 is 24. Therefore, the correct answer is 24.
2.
Find the mean of the set of data 12, 9, 6, 17, 20, 15, 12, 5.
Correct Answer
A. 12
Explanation
The mean of a set of data is found by adding up all the numbers in the set and then dividing by the total number of values. In this case, the set of data is 12, 9, 6, 17, 20, 15, 12, 5. Adding up all these numbers gives us a total of 96. Since there are 8 values in the set, we divide 96 by 8 to find the mean. 96 divided by 8 is 12, so the mean of the set of data is 12.
3.
Find the mode of the set of data 12, 13, 18, 10, 13, 18, 12, 10, 18, 15
Correct Answer
D. 18
Explanation
The mode of a set of data is the value that appears most frequently. In this set of data, the number 18 appears 3 times, which is more than any other number. Therefore, the mode of the set is 18.
4.
Find the outlier of the set of data 24, 37, 33, 31, 28, 25, 33, 12
Correct Answer
B. 12
Explanation
The outlier in a set of data is a value that is significantly different from the other values in the set. In this case, the numbers 24, 37, 33, 31, 28, 25, and 33 are all relatively close in value, but the number 12 is much smaller than the rest. Therefore, 12 is the outlier in this set of data.
5.
Dylan found the mean and median of this list of numbers:
1, 3, 3.
If the number 6 were added to the list, then...
Correct Answer
A. The mean would increase.
Explanation
When finding the mean, we sum up all the numbers in the list and divide by the total count. Currently, the mean of the list is (1+3+3)/3 = 2. If we add the number 6 to the list, the new sum would be (1+3+3+6) = 13. Dividing this sum by the new count of 4, we get a new mean of 13/4 = 3.25. Therefore, adding the number 6 to the list would increase the mean.
6.
The histogram shows the number of minutes students at Marlowe Junior High typically spend on household chores each day. How many students spend 61-80 minutes on chores?
Correct Answer
B. 11
Explanation
The histogram shows the number of minutes students at Marlowe Junior High typically spend on household chores each day. The bar representing the range 61-80 minutes has a height of 11, indicating that 11 students spend this amount of time on chores.
7.
The histogram shows the number of minutes students at Marlowe Junior High typically spend on household chores each day. How many students spend 60 minutes or less on chores?
Correct Answer
D. 18
Explanation
The histogram shows the number of students on the y-axis and the number of minutes spent on household chores on the x-axis. The bar representing 60 minutes or less is the last bar on the right side. The height of this bar is 18, indicating that 18 students spend 60 minutes or less on chores.
8.
Use the bar graph below. Approximately how many more students ride
in a car than walk?
Correct Answer
C. 100
Explanation
Based on the bar graph, the number of students riding in a car is represented by the height of the bar, which is 150. The number of students walking is represented by the height of the bar, which is 50. To find the difference, we subtract the number of students walking from the number of students riding in a car: 150 - 50 = 100. Therefore, approximately 100 more students ride in a car than walk.
9.
Use the line graph. By how many millions of dollars did sales increase from 1992 to 1993?
Correct Answer
B. $35 million
Explanation
The line graph shows the sales data for the years 1992 and 1993. By comparing the values on the graph, it can be observed that the sales increased by $35 million from 1992 to 1993.
10.
Decide which sampling method is used. You sample every sixth person at a grocery store to see what type of sports events they watch.
Correct Answer
B. Systematic Sampling
Explanation
Systematic sampling is the correct answer because the sampling method described in the question involves selecting every sixth person at a grocery store. In systematic sampling, the population is divided into a list or sequence, and then every nth individual is selected for the sample. This method ensures that the sample is representative of the population and provides an equal chance for each person to be selected.
11.
At Javier's summer job with a research company, he must get a random sample of people in a local town to answer a question about an upcoming election. Which method could he use to get a random sample?
Correct Answer
D. Selecting people randomly from the list of town residents
Explanation
Javier could use the method of selecting people randomly from the list of town residents to get a random sample. This method ensures that every resident in the town has an equal chance of being selected, thus providing a representative sample for the research.
12.
Which question is biased?
Correct Answer
B. "Do you prefer to sit on the couch and watch TV or do you like to exercise and stay in shape?"
Explanation
The question "Do you prefer to sit on the couch and watch TV or do you like to exercise and stay in shape?" is biased because it assumes that the person being asked does not already exercise and stay in shape. It presents a false dichotomy between being sedentary and being active, implying that one cannot do both. This question also implies that sitting on the couch and watching TV is inherently lazy or undesirable, while exercising and staying in shape is the preferred or ideal option.
13.
Which survey question is unbiased?
Correct Answer
C. "Do you prefer bringing lunch to school or eating school lunches?"
Explanation
The question "Do you prefer bringing lunch to school or eating school lunches?" is unbiased because it presents two options without any positive or negative bias towards either choice. It allows the respondent to express their preference without influencing them towards a particular answer.
14.
Decide which sampling method is used. Your teacher puts the names of all the students in your class into a box. He selects a class representative by drawing a name out of the box.
Correct Answer
A. Random sampling
Explanation
The correct answer is random sampling because the teacher is selecting a class representative by drawing a name out of the box, which gives an equal chance for each student to be selected. This method ensures that every student in the class has an equal opportunity to be chosen as the representative, making it a random selection process.
15.
Find the range of the set of data 12, 9, 6, 17, 20, 15, 12, 5.
Correct Answer
C. 15
Explanation
The range of a set of data is the difference between the maximum and minimum values. In this case, the maximum value is 20 and the minimum value is 5. The difference between these two values is 15, so the range of the set of data is 15.