I need step by step solution and explanation for the following question:

(Annuity) You have exactly 45 years to work until you plan on retiring. If you will make end-of-each month contributions into your 401k plan until you retire, and you earn 6% annually with monthly compounding, how much must you contribute each month (assume 45 years of making monthly payments into the account) to have exactly $3 million at retirement?