What are seven numbers that have a range of 10 and a mean of 12?

7 x 12 = 92 so you want to find seven data points that add up to 92.

1+2+3+4+5+6+71=92
2+3+4+5+6+7+65=92
and so on.

Now consider the range.
7+17+8+16+9+15+10+10=92 <- No good
8+18+9+17+10+16+14=92 <- Good

And that is how you do it.