Answer:
657 pounds
Explanation:
Given
Represent the amount of fertilizer with x and the yield with y.
So, we have:
![(x_1,y_1) = (70,630)](https://img.qammunity.org/2021/formulas/mathematics/college/s2o6s4vn9ejwi1kmoah0kfo1eifbvh0mgi.png)
![(x_2,y_2) = (100,900)](https://img.qammunity.org/2021/formulas/mathematics/college/nmyll25dobvo1kpxkw4u0b4jsqhgjzqstj.png)
Required:
Determine the yield (y) when fertilizer (x) is 73ft^3
Using linear interpolation, we have:
![y = y_1 + (x - x_1)((y_2 - y_1))/((x_2 - x_1))](https://img.qammunity.org/2021/formulas/mathematics/college/ffwabv7kzrehp2wqwipgyfud33bsc7fvoo.png)
Substitute the x and y values using
and
;
We have:
![y = y_1 + (x - x_1)((y_2 - y_1))/((x_2 - x_1))](https://img.qammunity.org/2021/formulas/mathematics/college/ffwabv7kzrehp2wqwipgyfud33bsc7fvoo.png)
![y = 630 + (x - 70)((900 - 630))/((100 - 70))](https://img.qammunity.org/2021/formulas/mathematics/college/4hwqsg948m4zqvy4ayxskiaclkohxfepgl.png)
![y = 630 + (x - 70)(270)/(30)](https://img.qammunity.org/2021/formulas/mathematics/college/c2utb2xfeny1cb58bwuz5gwjita222frzw.png)
![y = 630 + (x - 70)*9](https://img.qammunity.org/2021/formulas/mathematics/college/srjxu9emydkj56x4yhx4nma80v3ievqyaw.png)
Open bracket
![y = 630 + 9x - 630](https://img.qammunity.org/2021/formulas/mathematics/college/g7n8eaz4en2o0upwoynmmk42gy4982u1y8.png)
![y = 9x - 630+630](https://img.qammunity.org/2021/formulas/mathematics/college/qctpstlyzvhwy9rof0ami04qeco71sbeci.png)
![y = 9x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1qmza3e04ez1rr8byiurrayx8vjiplx9kk.png)
To solve for y when x = 73.
We simply substitute 73 for x
![y = 9x](https://img.qammunity.org/2021/formulas/mathematics/middle-school/1qmza3e04ez1rr8byiurrayx8vjiplx9kk.png)
![y = 9 * 73](https://img.qammunity.org/2021/formulas/mathematics/college/cbe0rn219mn518tytrj1qjjflvgzj368kw.png)
![y = 657](https://img.qammunity.org/2021/formulas/mathematics/college/8fzrrlw8jleuny6w4j7fggad99n1b5x8c1.png)
Hence, the yield for 73 cubic feet is 657 pounds