Question

A number is randomly selected from the set $\{6,7,8,8,8,10,10,11\}$. Find the probability the number will be less than the mean.

• A. $\frac{1}{4}$
• B. $\frac{3}{8}$
• C. $\frac{5}{8}$
• D. $\frac{3}{4}$
• E. $1$

Answer 1

The correct option is C $\frac{5}{8}$

Mean of given set is $\frac{(6+7+8+8+8+10+10+11)}{8}=\frac{68}{8}=8.5$
Number of ways of selecting a number from given set is $8$
Numbers of electing a number from given set such that number is less than mean is $5$
So, the probability is $\frac{5}{8}$