Compute the difference between the prices for each day; i.e., the difference between the B and C columns and enter that amount in the D column headed "differential" for each day. Compute the arithmetic average and standard deviation of the "differential" column. The commands are respectively: =AVERAGE(D2:D67) and =STDEV(D2:D67). Your arbitrage strategy will be to buy one stock and simultaneously sell the other "short." To be specific, when the spread reaches one standard deviation above the mean you will buy the lower priced stock and sell the higher priced one. Alternatively, when the spread reaches one standard deviation below the mean, you will buy the expensive stock and simultaneously sell the cheap one short. You would then refrain from subsequent trading until the spread returned to the mean. At that point you would close out your positions. That is, you would sell stocks you owned "long" and buy those you were "short." Articulate your trading "rules" in statements such as: "I would buy stock X and sell Y when the spread reached _. I would extinguish positions when the spread returned to ." Your "trigger points" will be the mean plus and/or minus one standard deviation. Indicate them. Submit your record of prices and "trading rules." As a footnote to your record, please define the terms "arbitrage" and "short sale." Also please write a sentence explaining the underlying theoretical premise upon which such an arbitrage is based; i.e., why should it work? This completes our project. It is due on the