Residents in a neighborhood determine the approximate number of dandelions in each yard. then, they treat some yards with a weed-killing substance. the residents want to answer the question “about how many dandelions are in your yard? ” to determine the effectiveness of the weed killer. from which group would it be best to take a sample?

all residents of the neighborhood
only residents who had their yards treated with weed killer
only residents who did not have their yards treated with weed killer
only residents who still have dandelions in their yards after treatment with weed killer

All residents of the neighborhood

Step-by-step explanation:

The residents want to answer the question “About how many dandelions are in your yard?” to determine the effectiveness of the weed killer. From which group would it be best to take a sample?

Hence, all residents must be surveyed for the same.

Duh that guy is righ because I got it right on it.

Step-by-step explanation:

answer: option a.

step-by-step explanation:

you know that the quadrilateral opqr ( a four sided figure) is inscribed in circle. this means that all its vertices are on the circle.

then, by definition, the opposite angles of the quadrilateral are supplementary, this means that the sum of their measures is 180 degrees.

you can observe in the figure that the angles ∠opq   and the angle ∠orq   are opposite, therefore:

then, can be used to d to calculate the measure of ∠opq