According to an advertisement, a strain of soybeans planted on soil prepared with a specified fertilizer treatment has a mean yield of 107 bushels per acre. Twenty farmers who belong to a cooperative plant the soybeans in soil prepared as specified. Each uses a 40-acre plot and records the mean yield per acre. The mean and variance for the sample of the 20 farms are
and
Find the rejection region used for determining if the mean yield for the soybeans is not equal to 107 bushels per acre. Use