3.22. The following table gives data on monthly changes in the spot price and the futures price for a certain commodity. Use the data to calculate a minimum variance hedge ratio.

Spot price change +0.50 +0.61 -0.22 -0.35 +0.79 Futures price change +0.56 +0.63 -0.12 -0.44 +0.60 Spot price change +0.04 +0.15 +0.70 -0.51 -0.41 Futures price change -0.06 +0.01 +0.80 - 0.56 -0.46