Question

The mean of 5 consecutive integers is 10. If the smallest of these is removed, what is the new mean? A.8.4 B.9.0 C.10.5 D.12.5

Answer 1

number 1 = x

number 2 = x + 1

number 3 = x + 2

number 4 = x + 3

number 5 = x + 4

then

`\begin{gathered} (x+x+1+x+2+x+3+x+4)/(5)=10 \\ (5x+10)/(5)=10 \\ (5x+10)/(5)\cdot5=10\cdot5 \\ 5x+10=50 \\ 5x+10-10=50-10 \\ 5x=40 \\ (5x)/(5)=(40)/(5) \\ x=8 \end{gathered}`

therefore the numbers are:

number 1 = 8

number 2 = 9

number 3 = 10

number 4 = 11

number 5 = 12

and the new media is:

`M=(9+10+11+12)/(4)=(42)/(4)=10.5`

answer: C. 10.5