4. We would like to invest money in commercial activities for a period of one year, under the following conditions: at the beginning, we invest 1,200 GEL. During the first three months, the income should increase by 8% every month. After three months, every month, we add 500 GEL to the increased amount, and starting from this moment, every month the income should increase by 14%. In both cases, additional income is charged at the end of the month. How much money will we have after one year? How to calculate it in excel?