A recent study reported the mean body mass index (BMI) for adults in the United States was 26.8. A researcher believes the mean BMI of marathon runners is less than 26.8. A random sample of 35 marathon runners had a mean BMI of 22.7 with a standard deviation of 3.1. The researcher will conduct a one-sample t-test for a population mean. Have the conditions for inference been met? A. Yes, all conditions have been met.
В. No, because the sample was not selected using a random method.
C. No, because marathon runners are not a representative sample of all adults in the United States.
D. No, because the shape of the distribution of the sample is not known.
E. No, because the sample size is not large enough to assume normality of the sampling distribution of the sample mean.