Answer: B. $16.13
Step-by-step explanation:
Formula : Sum of n observations = Mean x n
Given, 82 seniors earned an average $26.75 per student, 74 juniors earned an average $12.25 per student, 96 sophomores earned an average $15.50 per student, and 99 freshmen earned an average $10.85 per student.
Total students = 82+74+96+99 =351
Sum of earnings of 82 seniors = $26.75 x 82= $2193.5
Sum of earnings of 74 juniors = $12.25 x 74 = $906.5
Sum of earnings of 96 sophomores = $15.50 x 96 = $1488
Sum of earnings of 99 freshmen = $10.85 x 99 = $1074.15
Total earnings = $2193.5 + $906.5+ $1488 +$1074.15
= $5662.15
Average collection = (Total earnings) ÷ (Total students )
= $5662.15÷ 351
≈ $16.13
Hence, the average collection for a student in this school = 16.31
So, the correct option is B.
