Question 8 - I just can' figure out how to unstuck from here. I've come up to many changes on this implemantation, but I 've just got failed results. . Is there anyone could give some help?

lo, hi, mid are indexes while mid_number is number you are searching for in list. You are trying to compare mid_number with mid, basically you are trying to compare index (mid) with the number (mid_number) you are searching for. What you have to do is compare number you are searching for (mid_number) with the number that is stored in list at index mid. If list of numbers is called nums then you access the value stored at index mid in list nums by calling nums[mid]. So instead of having mid_number == mid you will have mid_number == nums[mid].