A study of traffic safety show a correlation of 0.57 between average speed of traffic and number of fatal accidents for a particular stretch of highway. This means that
A) drivers should speed up to get through this areas as quickly as possible
B) as speed increases, fatalities decrease
C) fatalities tend to increase as average speed increases
D) every 1 mile per hour increase in average speed increases the number of traffic fatalities by .57.

Question

Quizplus · Accepted Answer

A correlation of 0.57 indicates a moderately strong positive relationship between average speed and number of fatal accidents. This means that as average speed increases, fatalities tend to increase. It does not mean that drivers should speed up or that every 1 mile per hour increase in speed will increase the number of fatalities by 0.57. These are incorrect interpretations of correlation.

A Study of Traffic Safety Show a Correlation of 0