Matthew has a new job as business analyst. He plans to invest 12 percent of his annual salary after the tax into a retirement account at the end of every year for the next 30 years. Suppose that annual return is 5%, and his current after tax salary is 76k which grow 3% per year then:

1)Create a spreadsheet which shows Matthew the balance of retirement account for various levels of annual investments and returns. (EXCEL)

2)If Matthew aims to gain $1,500,000 at the end of the 30^th year, what percentage of his salary he should put in the investment annually.