A) Write the solution steps in Excel Program

B) what is the purpose of the question

C) Ensuring the validation of your program or calculations done above

D) what will be if changing the input of the question

4-12. Karen Perez runs an office supply store that also performs simple office services, such as copying. It is time to purchase a new high-speed copier and Karen has learned that machine uptime is a critical factor in selection. She has gathered the following data on reliability and maintainability for the three copiers she is considering. Given that all other factors are equal, which machine should Karen purchase? Copier Able Copy Business Mate Copy Whiz Mean Time Between Failures (Hours) 40 80 240 Mean Time to Repair (Hours) 1 4 8