1. A farmer in southern Illinois has knowledge of potato yields from 12 different farms he manages [21.5, 24.5, 18.5, 17.2, 14.5, 23.2, 22.1, 20.5, 19.4, 18.1, 24.1, 18.5] and wants to determine if those fields have a different yield than the standard yield of 20.

Use a one-sample t-test to determine if the farmer's current potato yield is significantly different than the standard yield.