Question

Exhibit 2-1 the numbers of hours worked (per week) by 400 statistics students are shown below. Number of hours frequency 0x10 20 10x20 80 20x30 200 30x40 100 ​ refer to exhibit 2-1. The percentage of students working between 10 and 20 hours is _____.

a. 80%
b. 20%
c. 25%
d. 75%

Answer 1

The percentage of statistics students working between 10 and 20 hours per week is 20%, which is calculated by dividing the frequency of the group (80 students) by the total number of students (400) and multiplying by 100.

Step-by-step explanation:

The question is asking us to find the percentage of statistics students who work between 10 and 20 hours per week, given the frequency distribution provided in Exhibit 2-1. According to the exhibit, 80 students work between 10 and 20 hours per week. Since the total number of students is 400, we calculate this percentage by taking the number of students in the given category (80 students) and dividing it by the total number of students (400), then multiplying by 100 to get a percentage.

The calculation is:

Percentage = (80 ÷ 400) × 100

Percentage = 0.20 × 100

Percentage = 20%

Therefore, the percentage of students working between 10 and 20 hours is 20%, which corresponds to option b.

Answer 2

b. 20%

Step-by-step explanation:

The distribution of number of hours worked by students is:

0 - 10 = 20

10 - 20 = 80

20 - 30 = 200

30 - 40 = 100

Total number of students = 400

We need to find the percentage of students working between 10 and 20 hours. From the above table we can see that number of students working between 10 and 20 hours is 80. Now we need to convert this into percentage. What we need to evaluate is what percentage of 400 is 80.

The formula for percentage is:

`\frac{\text{Concerned Value}}{\text{Total Value}} * 100\%`

Concerned value is 80, total value is 400. So using these in the formula we get:

`(80)/(400) * 100%\\\\  = 20\%`

Thus, 20% of the students are working between 10 and 20 hours.