Answer:
55.55 bushels.
Explanation:
Given,
4 soybean seeds per square foot = -1 bushel per acre, ( negative sign shows loss )
![\implies \frac{4\text{ soybeans}}{\text{ 1 square foot}}=\frac{-1\text{ bushel}}{\text{1 acre}}-----(1)](https://img.qammunity.org/2020/formulas/mathematics/college/hqhoapec0f9twfsy3fx2jb2rq89kue2uwf.png)
Let x be the the yield for 100 acres when 20 soybeans in a square yard is counted,
![\implies \frac{20\text{ soybeans}}{1\text{ square yard}}=\frac{x\text{ bushel}}{100\text{ acre}}](https://img.qammunity.org/2020/formulas/mathematics/college/k35bbftakctvomt0nhky0skf1qbf190dtu.png)
Now, 1 yard = 3 feet ⇒ 1 square yard = 9 square feet,
![\implies \frac{20\text{ soybeans}}{\text{ 9 square feet}}=\frac{x\text{ bushel}}{\text{100 acre}}----(2)](https://img.qammunity.org/2020/formulas/mathematics/college/xy9lkqyyz6owe1r5yir1ejb0oj0oe7xy83.png)
![(Equation (1))/(Equation (2))](https://img.qammunity.org/2020/formulas/mathematics/college/5alh2erdywjk9aci85xav29pcgdfpo0uw4.png)
![\implies (4/1)/(20/9)=(-1/1)/(x/100)](https://img.qammunity.org/2020/formulas/mathematics/college/nu39xu1g3p7qab44jzytq68ffqzoe97r9k.png)
![(36)/(20)=-(100)/(x)](https://img.qammunity.org/2020/formulas/mathematics/college/twp5mz6bpldzsxbef0ea14znq3xxg4j1rs.png)
![x=-(2000)/(36)\approx -55.55](https://img.qammunity.org/2020/formulas/mathematics/college/t4yl203e3det1uqywwemqvya3h36fyu7fv.png)
Hence, the yield loss is 55.55 bushel.