Find the best solutions to your questions at Westonci.ca, the premier Q&A platform with a community of knowledgeable experts. Discover in-depth answers to your questions from a wide network of professionals on our user-friendly Q&A platform. Get quick and reliable solutions to your questions from a community of experienced experts on our platform.

A farmer is tracking the amount of wheat his land yields each year. He finds that the function [tex]\( f(x) = -x^2 + 20x + 75 \)[/tex] models the crop yield in pounds per acre over [tex]\( x \)[/tex] years.

Find and interpret the average rate of change from year 5 to year 15.

A. The crop yield increased by 150 pounds per acre from year 5 to year 15.
B. The crop yield decreased by 15 pounds per acre from year 5 to year 15.
C. The crop yield decreased by 5 pounds per acre from year 5 to year 15.
D. The crop yield did not change from year 5 to year 15.


Sagot :

To solve this problem, we need to calculate the crop yield at two specific years (year 5 and year 16), then find the average rate of change between these years.

1. Finding the Crop Yield at Year 5:

We are given the function [tex]\( f(x) = -x^2 + 20x + 75 \)[/tex].

To find the yield at year 5:
[tex]\[ f(5) = -(5)^2 + 20(5) + 75 = -25 + 100 + 75 = 150 \][/tex]

Therefore, the crop yield at year 5 is 150 pounds per acre.

2. Finding the Crop Yield at Year 16:

Using the same function [tex]\( f(x) \)[/tex]:
[tex]\[ f(16) = -(16)^2 + 20(16) + 75 = -256 + 320 + 75 = 139 \][/tex]

Therefore, the crop yield at year 16 is 139 pounds per acre.

3. Calculating the Average Rate of Change:

The average rate of change of a function between two points [tex]\((x_1, f(x_1))\)[/tex] and [tex]\((x_2, f(x_2))\)[/tex] is given by:
[tex]\[ \text{Average Rate of Change} = \frac{f(x_2) - f(x_1)}{x_2 - x_1} \][/tex]

Here, [tex]\(x_1 = 5\)[/tex] and [tex]\(x_2 = 16\)[/tex]:
[tex]\[ \text{Average Rate of Change} = \frac{139 - 150}{16 - 5} = \frac{-11}{11} = -1.0 \][/tex]

Therefore, the average rate of change is [tex]\(-1.0\)[/tex] pound per acre per year.

### Interpretation:

- The crop yield in year 5 is 150 pounds per acre.
- The crop yield in year 16 is 139 pounds per acre.
- The average rate of change over this period is [tex]\(-1.0\)[/tex] pound per acre per year, which means that the crop yield is decreasing by 1 pound per acre each year on average between year 5 and year 16.

Given the multiple-choice options:

- The crop yield increased by 150 pounds per acre from year 5 to year 15.
- The crop yield decreased by 15 pounds per acre from year 5 to year 15.
- The crop yield decreased by 5 pounds per acre from year 5 to year 15.
- The crop yield did not change from year 5 to year 15.

None of these options directly match the analysis, but focusing on the fact that the yield is decreasing, the closest option with minimal interpretation could be a minor misstatement about the exact pounds:

- The crop yield decreased by 11 pounds from year 5 to year 16, not exactly any given years.
- To maintain selection integrity, correct statement attributes change till 5 to 16.

The correct interpretation based on the calculation should be: "The crop yield decreased by 11 pounds per acre from year 5 to year 16."
Thank you for trusting us with your questions. We're here to help you find accurate answers quickly and efficiently. We appreciate your visit. Our platform is always here to offer accurate and reliable answers. Return anytime. Westonci.ca is committed to providing accurate answers. Come back soon for more trustworthy information.