EXAMPLE 1 Calculating a point estimate

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Farmers work hard to increase the yield of their acreage. Yield represents the number of bushels of a crop produced per acre. Suppose we are interested in estimating the population mean yield for winter wheat across all 50 states. Shown here is the mean July 2014 yield for a sample of five states, in bushels, as published by the U.S. Department of Agriculture (USDA).

  1. Find the sample mean yield .
  2. Express as the point estimate of , the unknown population mean winter wheat yield for all 50 states.
State Yield (bushels)
California 85
Georgia 55
Illinois 67
Ohio 68
Texas 25

429

Solution

  1. The sample mean yield is calculated as

  2. The point estimate of , the unknown nationwide mean winter wheat yield for all 50 states, is 60 bushels per acre.

NOW YOU CAN DO

Exercises 11–14.