Cheryl wants to find the number of hours seventh-graders do homework each week. There are 297 girls and boys in seventh grade. W
hich is the best way for Cheryl to get a representative sample without spending too much time? A.) She can survey 15 of her friends in the school. B.) She can survey every sixth-grade student in the school. C.) She can randomly survey 50 girls in the entire school. D.) She can randomly survey 50 seventh-graders in the school.
Surveying 50 girls would include other grades outside of seventh grade and would not include boys. This would not be a representative sample of the population and would lead to invalid results.
The probability that the average salary between two groups is the same, is actually low. It could be close, but it's quite difficult to get the same exact amount.
