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?
a. random and biased
b. random and unbiased
c. nonrandom and biased
d. nonrandom and unbiased

C. nonrandom and biased

Step-by-step explanation:

In random sampling, there should be no pattern when designing a sample, but Li selected a sample in her first-period class. This means that Li's sample is not random.

Since 28 is too smaller than 600, the rest of the students can have different thinking from the her first -period class students. Therefore the sample must be biased.  

Therefore, option C is correct the sample explained by Li is non random and biased.

10.416 meters per second

step-by-step explanation:

distance=1 00 meters

time= 9.6 seconds in decimal form or 9 3/5 as a mixed number

average speed= 100/9.6

=10.416 meters per second or 10 52/125 as a mixed number.