Question

1. What is the probability that the new herbicide was effective in controlling weeds?2. What is the probability that weeds were effectively controlled when the existing herbicide was applied?3. What is the probability that ineffective results occurred when the new herbicide was used?

Answer 1

a. 0.94

b. 0.78

c. 0.06

Explanation:

We calculate the probability in each case taking into account the favorable cases by the total number of cases.

It was tested in total in 100 fields but for each herbicide it was tested in 50 fields, therefore:

`\begin{gathered} a. \\ \\ p=\frac{\text{ effective fields new herbicide}}{\text{ total fields new herbicide }}=(47)/(50)=0.94=94\% \\ \\ b. \\ \\ p=\frac{\text{ effective fields existing herbicide}}{\text{ total fields existing herbicides}}=(39)/(50)=0.78=78\% \\ \\ c. \\ \\ p=\frac{\text{ not effective fields new herbicide}}{\text{ total fields new herbicide}}=(3)/(50)=0.06=6\% \end{gathered}`