This problems seems to be missing information, or alternatively it is simple.
Means here seems to be the difference between consecutive terms of an arithmetic sequence. Thus, the answer in the first exercise consists of the numbers 10+1*5, 10+2*5, 10+3*5, ..., 40-2*5, 40-1*5. That is, you start from the lower limit and continue in increments equal to the mean until you reach the upper limit.
Hence, the answer in the second is x+y+2, x+y+4, x+y+6, x+y+8, ..., all the way to 4x-2y-2.
However, this is not a very satisfactory answer, since the first term might be larger than the last term, and there is no guarantee that their difference, 3x-3y, is divisable by two; consider x = 1 and y = 0 for a simple case where things go wrong, and irrational numbers for even more fun.
I suspect the book is not very good or that it provides some context that is missing from the question here.
tommi
·
2022-07-12T11:12:45Z (almost 2 years ago)