Asking for assistance is one thing. You just basically asked for someone to do the entire project for you.
The code to perform your project is extremely basic, & should be completed with little effort.
Prompt the user
Read the given result into a variable
Loop until that variable
Create a variable to hold the total of all results
For each loop, append the value to the variable with the total
Sort the results to find the highest & lowest
Dream.In.Code has a policy by which we prefer to see a good faith effort on your part before providing source code. Please post the code you have written in an effort to resolve the problem, and our members would be happy to provide some guidance. Be sure to include a description of any errors you are encountering as well.