You decide you will buy a stock only if it shows an overall increase over the next 30 days. the first 10 days, it has an average daily increase of 0.30. the next 10 days it has an average daily decrease of 0.45. the last 10 days, it has an average daily increase of 0.25 a. how much did the stock change over the first 10 days? b. how much did the stock change over the next 10 days? c. how much did the stock change over the last 10 days? d. how much did the stock change altogether? e. should you buy the stock?