please answer 13 and 14

13. The price of a good during the last five years is: $25 $30 $36 $43 $50 Calculate the index numbers using the last year as the base year and hence comment on the rise in prices during this period. 14. Table 3.13 shows the monthly index of sales of a good during the first four months of the year. Table 3.13 Month Apr Index 120 150 Jan Feb Mar 100 145 (a) Which month is chosen as the base year? (b) If sales in February are 3840, what are the sales in April (c) What is the index number in May if sales are 42567