Algebra 1 Word Problem

Question

That average weight of the top 5 caught at a fishing tournament was 12.3 pounds. Some of the weights of the fish are 12.8, 12.6, 11.8 and 9.7.  What was the weight of the heaviest fish?

Answer 1

to find the average you must sum all the numbers and divide by the number of observations. 

(12.8+12.6+11.8+9.7+x)/5=12.3

simplify and cross multiply we have 

46.9+x =61.5

so X = 14.6