Charts and Diagrams：练习题

A frequency distribution table shows that the frequency of the class interval \(10 - 19\) is 8. If the total frequency of all classes is 40, what is the relative frequency of this class interval?

In a pie chart representing the favorite subjects of 40 students, the sector for Mathematics has a central angle of \(90^\circ\). How many students chose Mathematics as their favorite subject?

The following data represents the weights (in kg) of 8 students: 42, 45, 48, 42, 50, 52, 42, 45. Find the mode of the data.

A histogram is constructed for the weights of 50 students. The frequency of the class interval \( 40 \text{ kg} \le w < 45 \text{ kg} \) is 12. What is the area of the bar representing this class if the width of each class interval on the horizontal axis is 5 units and the vertical axis represents frequency?

In a stem-and-leaf diagram, the stem represents the tens digit and the leaf represents the units digit. If a row is written as 3 | 0 2 2 5, which of the following is NOT a value in this row?

In a pie chart representing the favorite colors of \( 40 \) students, the sector for "Blue" has a central angle of \( 108^{\circ} \). How many students chose Blue?

The following data shows the test scores of \( 5 \) students: \( 60, 75, 80, 85, 90 \). If these scores are displayed in a broken-line graph, what is the increase in score from the 1st student to the 5th student?

A set of data consists of the heights (in cm) of \( 6 \) plants: \( 12, 15, 12, 18, 20, 15 \). If you create a stem-and-leaf diagram for this data using a stem of \( 10 \), how many leaves will be attached to the stem "1"?

The following data shows the number of books read by 10 students in a month: 2, 5, 3, 2, 8, 5, 5, 4, 7, 9.
(a) Construct a frequency distribution table for this data.
(b) Find the mean number of books read by the students.

In a school survey, 120 students were asked about their favorite sport. The results are as follows: Basketball (45 students), Football (35 students), Swimming (25 students), and Others (15 students).
(a) Calculate the percentage of students who chose Basketball.
(b) If this data is represented in a pie chart, calculate the angle of the sector representing 'Swimming'.