Canada Grade 8 Math Collecting, organizing, and

A survey was conducted to find out the favourite sport of students in a school. The results are shown in the table below. What is the mode of the data? | Sport | Number of Students | |-----------|--------------------| | Soccer | 15 | | Basketball| 20 | | Hockey | 10 | | Volleyball| 20 |

• Soccer

• Basketball

• Hockey

• Volleyball

Answer explanation

The mode is the value that appears most frequently. In this survey, both Basketball and Volleyball have the highest count of 20 students. However, since Basketball is listed first, it is considered the mode.

A class of 30 students was surveyed about their favourite ice cream flavour. The results were: 10 students liked chocolate, 12 liked vanilla, and 8 liked strawberry. What is the probability that a randomly selected student likes vanilla?

Answer explanation

To find the probability that a randomly selected student likes vanilla, divide the number of students who like vanilla (12) by the total number of students (30). Thus, P(Vanilla) = 12/30 = 2/5.

Which of the following is a primary source of data?

• A textbook

• A newspaper article

• A survey you conducted

• An online blog

Answer explanation

A survey you conducted is a primary source of data because it involves original data collection. In contrast, a textbook, newspaper article, and online blog are secondary sources that interpret or summarize existing information.

• 12

• 14

• 16

• 18

Answer explanation

To find x, set up the equation for the mean: (4 + 8 + 12 + x) / 4 = 10. Simplifying gives 24 + x = 40, so x = 16. Thus, the value of x is 16.

A die is rolled once. What is the probability of rolling a number greater than 4?

Answer explanation

A die has 6 faces numbered 1 to 6. The numbers greater than 4 are 5 and 6, which are 2 outcomes. Therefore, the probability is \( \frac{2}{6} = \frac{1}{3} \). Thus, the correct answer is \( \frac{1}{3} \).

Which of the following graphs is best for showing the distribution of a single categorical variable?

• Line graph

• Bar graph

• Scatter plot

• Histogram

Answer explanation

A bar graph is ideal for displaying the distribution of a single categorical variable, as it visually represents the frequency of each category. Other options like line graphs and scatter plots are better suited for continuous data.

A box contains 5 red, 3 blue, and 2 green marbles. What is the probability of drawing a blue marble?

Answer explanation

To find the probability of drawing a blue marble, divide the number of blue marbles (3) by the total number of marbles (10). Thus, the probability is \( \frac{3}{10} \), which is the correct answer.

What is the median of the following data set: 3, 7, 9, 15, 18?

• 7

• 9

• 12

• 15

Answer explanation

To find the median, arrange the data in order: 3, 7, 9, 15, 18. The median is the middle value, which is 9 in this case, as it is the third number in the ordered list.

If the range of a data set is 20 and the smallest value is 5, what is the largest value?

• 15

• 20

• 25

• 30

Answer explanation

The range is calculated as the largest value minus the smallest value. Given the range is 20 and the smallest value is 5, we can set up the equation: largest value - 5 = 20. Solving this gives the largest value as 25.

Which of the following is a continuous variable?

• Number of students in a class

• Number of books on a shelf

• Height of students

• Number of cars in a parking lot

Answer explanation

Height of students is a continuous variable because it can take any value within a range, unlike the other options which are discrete and countable.