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How much do the percentages add up to?
Find each central angle by multiplying the percent of students that use a method by 360^(∘).
Use the formula to find the area of a sector of a circle with the central angles found in the previous part.
The percentages add up to 100 %.
Bus: 234^(∘)
Walk: 90^(∘)
Other: 36^(∘)
Bus: about 8.17 in^2
Walk: about 3.14 in^2
Other: about 1.26 in^2
A circle graph is appropriate to represent the data in the table because the percentages add up to 100 % and we can use an entire circle.
| Method | Percent of students |
|---|---|
| Bus | 65 % |
| Walk | 25 % |
| Other | 10 % |
Let's begin by drawing a circle with a radius of 2 inches.
We have to divide this circle into three sectors of different sizes to represent the data given in the table. To do that, we need to find the central angle used for each sector.
| Method | Percent of students |
|---|---|
| Bus | 65 % |
| Walk | 25 % |
| Other | 10 % |
Because 65 % of the students get to school using a bus, the central angle is equal to 65 % multiplied by 360^(∘). 65 % * 360^(∘) = 0.65* 360^(∘) = 234^(∘) From the above, the sector that will represent the percent of students going to school in bus has a central angle of 234^(∘). Similarly, let's find the central angles of the other two sectors.
| Method | Percent of students | Central angle |
|---|---|---|
| Bus | 65 % | 64 % * 360^(∘) = 234^(∘) |
| Walk | 25 % | 25 % * 360^(∘) = 90^(∘) |
| Other | 10 % | 10 % * 360^(∘) = 36^(∘) |
Finally, let's make a graph representing the data in the table.
In this part, we will find the area of each sector drawn in Part B. Let's label some points on it and mark the central angles.
| Method | Percent of students | Central Angle | Area (in^2) |
|---|---|---|---|
| Bus | 65 % | 234^(∘) | A_1 = 234^(∘)/360^(∘)* π (2)^2 ≈ 8.17 |
| Walk | 25 % | 90^(∘) | A_2 = 90^(∘)/360^(∘)* π (2)^2 ≈ 3.14 |
| Other | 10 % | 36^(∘) | A_3 = 36^(∘)/360^(∘)* π (2)^2 ≈ 1.26 |