Final answer:
The arithmetic average return for the Home Grown Grains stock over the past four years is 14.05 percent, calculated by adding the yearly returns and dividing by four.
Step-by-step explanation:
To calculate the arithmetic average return for the Home Grown Grains stock over the past four years, you simply add up the individual yearly returns and then divide by the number of years. The individual returns are 28.7 percent, 2.6 percent, 13.1 percent, and 11.8 percent.
Add these percentages together: 28.7 + 2.6 + 13.1 + 11.8 equals 56.2 percent.
Now divide by the number of years, which is four: 56.2 percent divided by 4 equals 14.05 percent. This is the arithmetic average return for the stock over this period.