45% of all marathon runners also enjoy biking. If many samples of 60 marathon runners are taken and the proportion of those who also enjoy biking is calculated for each sample, what will be the approximate value of the mean of the sample proportions?
A. 0.30
B. 0.45
C. 0.60
D. 0.75
A. 0.30
The mean of the sample proportions is equal to the true population proportion, which is 0.45.