The sterplot shows the relationship between the length of time y , in hours, a certain bird spent in flight

Question

The sterplot shows the relationship between the length of time $y$ , in hours, a certain bird spent in flight and the number of days after January $11$ , $x$ .

What is the average rate of change, in hours per day, of the length of time the bird spent in flight on January $13$ to the length of time the bird spent in flight on January $15$ ?

Accepted Answer

The correct answer is 9 2 . It's given that the sterplot shows the relationship between the length of time y , in hours, a certain bird spent in flight and the number of days after January 11 , x . Since January 13 is 2 days after January 11 , it follows that January 13 corresponds to an x -value of 2 in the sterplot. In the sterplot, when x = 2 , the corresponding value of y is 6 . In other words, on January 13 , the bird spent 6 hours in flight. Since January 15 is 4 days after January 11 , it follows that January 15 corresponds to an x -value of 4 in the sterplot. In the sterplot, when x = 4 , the corresponding value of y is 15 . In other words, on January 15 , the bird spent 15 hours in flight. Therefore, the average rate of change, in hours per day, of the length of time the bird spent in flight on January 13 to the length of time the bird spent in flight on January 15 is the difference in the length of time, in hours, the bird spent in flight divided by the difference in the number of days after January 11 , or 15 - 6 4 - 2 , which is equivalent to 9 2 . Note that 9/2 and 4.5 are examples of ways to enter a correct answer.

Question 661893