Question

Find the 3 arithmetic means between between 18 and -10

Answer 1

we have the following:

The arithmetic means are the numbers that would be part of an arithmetic sequence where 18 is the first term and -10 is the fifth term (in this case); notice that it gives tree numbers in the sequence between the two. I like this

`18\rightarrow x\rightarrow x\rightarrow x\rightarrow-10`

so:

`\begin{gathered} 18+x+x+x+x=-10 \\ 18+4x=-10 \\ 4x=-10-18 \\ x=-(28)/(4) \\ x=-7 \end{gathered}`

therefore,

the 1st arithmetic mean is:

`18-7=11`

the 2nd arithmetic mean is:

`11-7=4`

the 3rd arithmetic mean is:

`4-7=-3`