Four books have 3, 4, 6 and 8 chapters. What is the mean number of chapters per book? Enter the number of chapters. Give your answer as a decimal.

Explication

The chapter counts total 3 + 4 + 6 + 8 = 21, and 21 divided by 4 books gives a mean of 5.25 chapters. Rounding the result to a whole number because the counts are whole numbers throws away part of the answer, since a mean is a balancing figure and need not match any value in the data set.