Now, use your previously-computed value as an approximation for sigma, and compute how many ears of the experimental corn the researcher needs in the study. don't forget, the margin of error and confidence level have already been given to you in a previous problem.

When used-car dealers signal the quality of a used car with a warranty, a. buyers believe the signal because the cost of a false signal is high b. it is not rational to believe the signal because some used-car dealers are crooked c. the demand for lemons is eliminated d. the price of a lemon rises above the price of a good used car because warranty costs on lemons are greater than warranty costs on good used cars