Li designed a survey to determine how comfortable students at her middle school are with fractions. there are 600 students in her middle school. the students are equally distributed among grade levels. she selected a sample of 28 students in her first-period class. which best explains li’s sample?

The correct answer to this is:

Nonrandom and biased

The method of Li’s sampling has a tendency that some elements or portion in the population has no chance of selection. Further, it was not stated which portion of the population she obtained the sample thus we cannot accurately determine the probability of selection. This kind of sampling results in a bias. A biased sampling is a type of nonrandom sampling. 

7x − y = 23

Step-by-step explanation:

The equation of line shown using the two points would be:

We know perpendicular line's slope (the number before x) would be "negative reciprocal of this, hence the equation of the perpendicular line would take the form:

Since it goes through (4,5), we can plug in 4 in x and 5 in y to figure out b:

So the equaiton is  y = 7x - 23

In standard form it is: 7x - y = 23