Question

A study was conducted on the relationship between speeds of cars and gas mileage. The correlation coefficient was 0.45. Later, the researchers found the speedometers read 5 mph too high. Researchers recomputed the coefficient. The new value will be:

Answer 1

Answer:

0.45

Step-by-step explanation:

The correlation coefficient is used to measure the relationship between how two variables change. In this question, the two variables are cars speed and gas mileage. Since the speedometers were wrong as they were 5 mph too high in a constant manner, then the correlation between how changes in speed affect gas mileage will not be changed.

For example, if we are measuring how an increase of 15 mph decreased gas mileage, we are looking at the change in speed and it is the same if we start with 75 mph and then increase speed to 90 mph, or if we start with 45 mph and then increase to 60 mph. The change in speed for both cases will remain unchanged at 10 mph.

Now, since we have seen that the change in speed remains unchanged and since correlation coefficient is a measure of the relationship between how two variables change, then the new value of the correlation coefficient will remain the same as 0.45.