The Iowa State University Agriculture Research Team is concerned about the impact of the recent drought on the productivity of the state’s corn crop. During the last 10 years, Iowa’s corn crop has averaged 32.4 bushels per acre per year. Final figures on this year’s yields will not be in for another 6 months, but the team needs to estimate yields now in case the governor decides to apply for federal disaster aid. A sample of 100 acres reveals a mean of 22.4 bushels, with a standard deviation of 15.7. Based on this sample, present a hypothesis and a null hypothesis, and evaluate them. In plain English, state what you have found. Then place an 80% confidence limit around your best estimate of the mean yield.