10.126 [EX10-126] Several counties in Minnesota and Wisconsin were randomly selected, and information about the 2001 sweet corn crop was collected. The following yield rates in tons of sweet corn per acre harvested resulted.

Yield, MN 5.90 6.50 6.20 5.90 6.20 5.70 5.91 5.90 6.00 5.60 6.51 6.30 Yield, WI 7.80 6.80 7.00 5.30 6.50 6.90 6.60 5.70 6.60 6.00 6.20 Source: http://www.usda.gov/nass/graphics/county01/data/vsc01.csv

a. Is there a difference in the variability of county yields as measured by standard deviation of yield rate? Use   0.05.

b. Assuming normality in yield rates, is the mean yield rate in Wisconsin significantly higher than the mean yield rate in Minnesota? Use   0.05.