"The variable userNumber should be used for storing the input the user gives you. The variable maxVal keeps track of the largest integer found so far. In the loop, prompt and store the user's number. Then check, if userNumber is positive and userNumber is greater than maxVal. If it is, then update maxVal to equal userNumber. Repeat this process until userNumber is equal to the SENTINEL variable."

Need help on this question and can you explain how as well?

Again, modify the while loop to utilize tolower() or toupper().  Create two more functions (options #3 and #4 in your menu) by taking the to_kilograms() and to_pounds() functions and modifying them to use reference variables instead of normal pass by value variables. Name them: to_kilograms_ref() to_pounds_ref() Create another two functions (options #5 and #6 in your menu) by taking the to_kilograms() and to_pounds() functions and modifying them to use pointers instead of normal pass by value variables. Name them: to_kilograms_ptr() to_pounds_ptr() Your new Menu should look like this, which includes what type of variables are being used: MENU 1. Kilograms to Pounds (pass by value) 2. Pounds to Kilograms (pass by value) 3. Kilograms to Pounds (pass by reference) 4. Pounds to Kilograms (pass by reference) 5. Kilograms to Pounds (using pointers) 6. Pounds to Kilograms (using pointers)   Example:   #include <iostream> #include <cmath>…

please don't change variable names