Which student performed the best on the test when compared to the rest of their class?

2nd period: mean was 17.1 and standard deviation was 1.2 Sally scored a 18

4th period: mean was 18.9 and standard deviation was 0.4 --- Chloe scored a 20

3rd period: mean was 13.5 and standard deviation was 3.7 --- Ronald scored a 17

1st period: mean was 15.3 and standard deviation was 2.4 -- Danny scored a 19

it is b)

hope this : )

step-by-step explanation:

details

step-by-step explanation:

proportions are fractions that equal to each other. so if two fractions are the same, they are proportional.

let's check the answers to see if they are proportional.

question a is not proportional because you can't turn 1.5/3 to 3/9. if you try to multiply 1.5/3 by 2 or 3, you wont get 3/9. it's impossible to make the fractions the same.

question b is not proportional because you can't turn 22/33 to 4/6. 33 can't go into 6.

question c is proportional because when you multiply 2 and 3 by 71, you would get 142/213, and those fractions equal to each other

question d is proportional because when you divide 14 and 7 by 2, you would end up with 7/3.5, and those fractions equal to each other.