13) a survey of 120 students was conducted. it was found that 72 students watched volleyball, and 45 of…
13) a survey of 120 students was conducted. it was found that 72 students watched volleyball, and 45 of these students were boys. of the students who watched tennis, 65% were girls. complete the two - way frequency table below showing the number of boys and girls who watched each sport.
Answer
Explanation:
Step1: Find number of girls who watched volleyball
The total number of students who watched volleyball is 72 and the number of boys who watched volleyball is 45. So the number of girls who watched volleyball is $72 - 45=27$.
Step2: Find number of students who watched tennis
The total number of students surveyed is 120 and 72 watched volleyball, so the number of students who watched tennis is $120 - 72 = 48$.
Step3: Find number of girls and boys who watched tennis
Since 65% of the students who watched tennis were girls, the number of girls who watched tennis is $0.65\times48 = 31.2\approx31$ (we assume we are dealing with whole - number of students, and we round). The number of boys who watched tennis is $48-31 = 17$.
Step4: Find total number of boys and girls
The total number of boys is $45 + 17=62$. The total number of girls is $27+31 = 58$.
Answer:
| Boys | Girls | Total | |
|---|---|---|---|
| Volleyball | 45 | 27 | 72 |
| Tennis | 17 | 31 | 48 |
| Total | 62 | 58 | 120 |