Among fatal plane crashes that occurred during the past 70 years, 304 were due to pilot error, 54 were due to other human error, 219 were due to weather, 614 were due to mechanical problems, and 379 were due to sabotage. Construct the relative frequency distribution. What is the most serious threat to aviation safety, and can anything be done about it? Complete the relative frequency distribution below. Relative Cause Frequency Pilot error Other human error Weather % Itten Mechanical problems % Sabotage % (Round to one decimal place as needed.) What is the most serious threat to aviation safety, and can anything be done about it? A. Sabotage is the most serious threat to aviation safety. Airport security could be increased B. Mechanical problems are the most serious threat to aviation safety. New planes could be better engineered. O C. Pilot error is the most serious threat to aviation safety. Pilots could be better trained. O D. Weather is the most serious threat to aviation safety. Weather monitoring systems could be improved