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 it is arranged in ascending or descending order. In this case, the set of data is 23, 13, 18, 29, 32, 25. When arranged in ascending order, the set becomes 13, 18, 23, 25, 29, 32. The middle value is 25, making it the median of the given set of data.
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 calculated by finding the sum of all the numbers in the set and dividing it by the total number of values. In this case, the sum of the numbers 12, 9, 6, 17, 20, 15, 12, and 5 is 96. Since there are 8 numbers in the set, the mean is 96 divided by 8, which equals 12. Therefore, the correct answer 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 three 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 significantly differs from the other values. In this case, the set of data is 24, 37, 33, 31, 28, 25, 33, and 12. The value 12 is the outlier because it is much smaller than the other values in the set.
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 add up all the numbers in the list and divide by the total count. In the original list, the mean is (1+3+3)/3 = 7/3. If we add 6 to the list, the new sum would be (1+3+3+6) = 13. And the new count would be 4. So, the new mean would be 13/4, which is greater than 7/3. Therefore, the mean would increase if the number 6 were added to the list.
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 students on the y-axis and the range of minutes spent on chores on the x-axis. The bar for the range 61-80 minutes has a height of 11, indicating that 11 students spend 61-80 minutes 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 of the histogram. 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 who ride in a car is represented by the height of the bar, which is 150. The number of students who walk is represented by the height of the bar, which is 50. To find the difference, we subtract the number of students who walk from the number of students who ride 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 increasing from 1992 to 1993. The y-axis represents the sales in millions of dollars. By comparing the values on the graph, it can be observed that the sales increased by $35 million from 1992 to 1993. Therefore, the correct answer is $35 million.
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 the grocery store. This method follows a systematic approach of selecting every nth element from a population, in this case, every sixth person. Random sampling involves selecting individuals randomly from the population without any specific pattern or order, while convenience sampling involves selecting individuals who are readily available and easily accessible.
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 can get a random sample by selecting people randomly from the list of town residents. This method ensures that every resident in the town has an equal chance of being selected, which helps to eliminate bias and increase the representativeness of the sample. By randomly selecting from the list, Javier can obtain a diverse sample that accurately reflects the population of the local town.
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 exercise and stay in shape if they prefer to sit on the couch and watch TV. It presents a false dichotomy by suggesting that there are only two options and that one option is associated with laziness or lack of physical activity.
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 does not contain any leading or persuasive language that could influence the respondent's answer. It presents two options without suggesting any preference or favoring one over the other. This allows the respondent to provide their honest opinion without any external influence.
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. This method ensures that every student in the class has an equal chance of being selected, making it a random and unbiased sampling technique.
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 largest and the smallest values in the set. In this case, the largest value is 20 and the smallest value is 5. Therefore, the range is 20 - 5 = 15.
16.
A number cube with the numbers 1 through 6 is rolled. Find the probability of rolling a number greater than 6.
Correct Answer
C. 0
Explanation
The question asks for the probability of rolling a number greater than 6 on a number cube with numbers 1 through 6. Since there is no number greater than 6 on the cube, it is impossible to roll a number greater than 6. Therefore, the probability of rolling a number greater than 6 is 0.
17.
A number cube with the numbers 1 through 6 is rolled. Find the probability of rolling a number less than or equal to 6.
Correct Answer
B. 1
Explanation
The probability of rolling a number less than or equal to 6 is 1, because all the numbers on the number cube are less than or equal to 6. Therefore, no matter which number is rolled, it will always be less than or equal to 6.
18.
If you spin the spinner, what is the probability of the pointer landing on Y?
Correct Answer
B. 1/8
Explanation
The probability of the pointer landing on Y is 1/8 because there are 8 equally likely outcomes on the spinner and only one of them is Y. Therefore, the probability of landing on Y is 1 out of 8.
19.
If you spin the spinner, what is the probability of the pointer landing on G?
Correct Answer
B. 25%
Explanation
The probability of the pointer landing on G is 25%. Since there are four equally likely outcomes (G, A, B, C) and only one of them is G, the probability is 1 out of 4, which can be simplified to 25%.
20.
You mix the letters S, E, M, I, T, R, O, P, I, C, A, and L thoroughly. Without looking, you draw one letter. Find P(I) as a fraction, a decimal, and a percent.
Correct Answer
D. 1/6, 0.17, 16.7%
Explanation
After mixing the letters thoroughly, there are a total of 12 letters. The letter "P" appears only once in the given letters. Therefore, the probability of drawing the letter "P" is 1 out of 12, which can be written as the fraction 1/12. In decimal form, this is 0.083, and in percentage form, it is 8.3%.
21.
There are 10 crayons in a box. Two are orange. A crayon is selected at random. Find the probability that it is NOT orange.
Correct Answer
A. 4/5
Explanation
The probability of selecting a crayon that is not orange can be determined by dividing the number of crayons that are not orange by the total number of crayons. In this case, there are 10 crayons in total and 2 of them are orange. Therefore, there are 8 crayons that are not orange. Dividing 8 by 10 gives us the probability of 4/5 that the selected crayon is not orange.
22.
Suppose you have the spinner and cards shown. Use a tree diagram to find the possible outcomes for spinning the spinner once and choosing a card. What is the total number of outcomes?
Correct Answer
A. 10 outcomes
Explanation
The spinner has 5 sections labeled A, B, C, D, and E. The cards have 2 sections labeled 1 and 2. To find the total number of outcomes, we multiply the number of options for spinning the spinner (5) by the number of options for choosing a card (2). This gives us 10 outcomes in total.
23.
At a pizza parlor, Tisha has a choice of pizza toppings and sizes. The topping choices are pineapple, ham, and black olives. The size choices are mini and small. Which tree diagram shows the number of possible one topping pizza combinations that Tisha can order?
Correct Answer
C.
24.
A coin is tossed and a single number cube is rolled. What is the probability that the coin shows heads and the number cube shows 5? (Hint, make a sample space)
Correct Answer
C. 1/12
Explanation
The probability of an event happening is calculated by dividing the number of favorable outcomes by the total number of possible outcomes. In this case, there is 1 favorable outcome (coin shows heads and number cube shows 5) out of a total of 12 possible outcomes (2 outcomes for the coin and 6 outcomes for the number cube). Therefore, the probability is 1/12.
25.
A bag contains 5 purple marbles and 7 yellow marbles. A yellow marble is drawn and not replaced. Then a second marble is drawn. What is the probability that the second one is purple?
Correct Answer
C. 5/11
Explanation
When a yellow marble is drawn and not replaced, there are now 4 purple marbles and 7 yellow marbles left in the bag. The total number of marbles left in the bag is 11 (4 purple + 7 yellow). Therefore, the probability of drawing a purple marble on the second draw is 4/11.