STAR Elyse runs a second-hand book business out of her home where she advertises and sells the books over the internet. Hor small business is becoming quite successful and she is considering purchasing an upgrade to her computer system that will give her more reliablo uplime. The cost is $5000 She expects that the investment will bring about an annual savings of $2000, due to the fact that her system will no longer suffer long failures and thus she will be able to sell more books What is the payback period on her investment, assuming that the savings accrue over the whole year