how much greater were his earnings with week than without?

Question

Scott earned $35, $40, $40, $25, and $45 for 5 weeks of part-time work. During a school break, he worked-full-time for one week and earned $187. How much greater were his mean weekly earnings with the full-time week included than without it? 

Answer 1

The mean is the arithmetic average.  Without the full-time wages, Scott's average weekly earnings were:

 

($35 + $40 + $40 + $25 + 45)/(5 weeks) = $185/5 = $37 per week

 

With his full-time earnings:

 

($35 + $40 + $40 + $25 + 45 + $187)/(6 weeks) = $372/6 = $62 per week

 

The difference is:

 

$62 - $37 = $25 per week