The answer is B, Decrease of 72.
If the mode is 8, then 8 actually shows up in the data set. This is not true of 7 or 5.

Multiply 20 by 5 to get 100 so multiply the 3 by 5 also to get 15% of the days.
What you need to do is that you plug p=3 into the expression [(5.4p+5)+(8+3.2p)]/2 and you have:
[(5.4*3+5)+(8+3.2*3)]/2
= (21.2+ 17.6)/2
= 38.8/2
= 19.4
The average of the two boys' points is p=3 is 19.4 points~
Answer:
Can You Make the Question Clear Please!?