QCAA General Mathematics Bivariate data analysis 1

This is the raw count of students who drive (12), not the percentage. To find the percentage, you must divide this count by the total number of students.

This value represents the percentage of the entire sample (staff and students combined) who are students driving their own car ($\frac{12}{80} = 15\%$), rather than the percentage of just the student group.

First, calculate the total number of students: $48 + 12 = 60$. Then, divide the number of students who drive by the total number of students: $\frac{12}{60} = 0.2$, which is $20\%$.

This figure represents the percentage of all drivers who are students ($\frac{12}{30} = 40\%$), rather than the percentage of students who drive.

This is simply the raw count of field athletes who prefer brand Y (12). To find the percentage, you must divide this count by the total number of field athletes.

This represents the percentage of the total population (80 athletes) who are field athletes preferring brand Y ($\frac{12}{80} = 15\%$). The question asks specifically for the percentage of field athletes.

To find the percentage of field athletes who prefer brand Y, divide the number of field athletes preferring Y (12) by the total number of field athletes (40): $\frac{12}{40} = 0.30$ or $30\%$.

This calculates the percentage of athletes preferring brand Y who are field athletes ($\frac{12}{30} = 40\%$). You used the column total (Total preferring Y) as the denominator instead of the row total (Total Field athletes).