Write the 2-digit number that matches the clues. my number has a tens digit that is 8 more than the ones digit. zero is not one of my digits.

Firstly attention should pe paid to the exact words given in the problem and then only the answer can be easily deduced.
It is a 2 digit number and that is said in the problem
Now For the tens digit it has been said that it is 8 more than the ones digit. The ones digit cannot be zero and that is already mentioned in the problem.
So if we take the ones digit to be 1, then the tens digit will be= 8 +1
                                                                                                 = 9
Now if we take the ones digit to be 2, then the tens digit will be = 2 + 8
                                                                                                     = 10
So it cannot be 2 as the tens digit takes the number to a 3 digit number and it is not possible.
So the answer to this problem is 91.

Cthe residual plot for model 1 has a non random pattern and is a good fit for the data