A study was undertaken at the Virginia Polytechnic Institute and State University to determine if fire can be used as a viable management tool to increase the amount of forage available to deer during the critical months in late winter and early spring. Calcium is a required element for plants and animals. The amount taken up and stored in the plant is closely correlated to the amount present in the soil. It was hypothesized that a fire may change the calcium levels present in the soil and thus affect the amount available to the deer. A large tract of land in the Fish burn Forest was selected for a prescribed burn. Soil samples were taken from 12 plots of equal area just prior to the burn, and analyzed for calcium. Post burn calcium levels were analyzed from the same plots. These values, in kilograms per plot, are presented in the following table: Construct a 95% confidence interval for the mean difference in the calcium level that is present in the soil prior to and after the prescribed burn. Assume the distribution of differences of calcium levels to be approximatelynormal.

Calcium Level (kg/plot) Plot Preburn Postburn 50 50 82 64 82 73 77 6. 18 45 18 3 4 18 6 32 54 23 45 36 18 10 11 12 54 9.