The mean number of hours that Raphael worked over the past four weeks is 37.75. If he works 40 hours this week, what will the mean number of hours be that he will have worked over the five-week period?

What is the five-week mean?

Multiply 37.75 x 4 to get the total number of hours Raphael worked the past 4 weeks. (The mean is just the total number divided by the number of parts).

37.75 x 4 = 151

Then, add 40 to that total to get the new total.

151 + 40 = 191

Now, divide that number by 5 (as in 5 weeks, the new number of parts).

191/5 = 38.2 hours

The mean for the first four weeks:

Total hours in 4 weeks / 4 = average of four weeks.

Total hours in 4 weeks = 37.75 x 4

= 151

Total hours in 5 weeks = 151 + 40

= 191

5-week mean = 191 / 5

= 38.2