Health researcher is interested in finding whether or not speed at which people walk is associated to their cholesterol levels. He chooses 100 adult volunteers at random, checks their cholesterol levels, and then times each one while they walk stretch of 100 yards. He is shocked at results: simple regression between thewalk times and cholesterol levels has R2 of 0.98 and slope of regression line is 0.7. Would he be justified in concluding that walking slowly may cause high cholesterol or that high cholesterol may influence walking speed? Explain why or why not.