Asurvey was conducted of 250 pediatricians on the average age of their patients. a sample mean of 8.3 years was determined, with a standard deviation of 1.8 years. assuming a 90% confidence level, which of the following statements holds true? a. as the sample size is too small, the margin of error cannot be trusted. b. as the sample size is too small, the margin of error is ±1.029. c. as the sample size is appropriately large, the margin of error is ±0.187. d. as the sample size is appropriately large, the margin of error is ±0.014.