Final answer:
To find the total number of students in year 1, set up a proportion using the number of students with black hair. Substitute the proportion of the black hair section into the equation to solve for x, the total number of students in year 1.
Step-by-step explanation:
The pie chart shows the hair colors of students in year 1. It is mentioned that 15 students had black hair. In a pie chart, each section represents a percentage or proportion of the whole. To find the total number of students in year 1, we need to determine what proportion the black hair section represents and then use that proportion to find the total number of students.
In this case, if 15 students represent a certain proportion of the whole, we can set up a proportion:
15 students / x students = proportion of black hair section / 100% (whole)
Cross multiplying, we get:
15 * 100% = x * proportion of black hair section
Simplifying, we have:
1500% = x * proportion of black hair section
To find the proportion of the black hair section, we need to know the measure of the angle or the percentage it represents in the pie chart.
Once we have that information, we can substitute it into the equation and solve for x, which will give us the total number of students in year 1.