The number of sit-ups that all tenth-grade girls can do in 5 minutes is normally distributed. Beth surveyed 20 of her fellow intramural tennis players, all tenth-grade girls, and determined the mean number of sit-ups they could do. Can she make an inference about the population mean for all tenth-grade girls based on the sample?
A
No, because the sample size was not big enough.B
No, because she did not use a simple random sample.C
Yes, because the sample size was big enough.D
Yes, because she used a simple random sample.