Final answer:
To find the value of k, we can use the average rate of change formula. The average rate of change on the interval [7, 21 - k] is equal to the difference in the y-values divided by the difference in the x-values. Solving for k gives k = 0.25.
Step-by-step explanation:
To find the value of k, we can use the average rate of change formula. The average rate of change on the interval [7, 21 - k] is equal to the difference in the y-values divided by the difference in the x-values. Using the given points, we have:
Average rate of change = (4k - (3+1k)) / (-2 - 7) = 0.25
Now we can solve for k:
4k - 3 - k = 0.25(-2 - 7)
3k - 3 = -2.25
3k = -2.25 + 3
3k = 0.75
k = 0.75/3
k = 0.25