Mrs. sparks is a 9th grade algebra 1 teacher. she teaches three algebra 1 courses and all the classes recently took a chapter exam. below are the scores.

class 1 45 68 77 90 90 95 100 100 86 90 50 55
class 2 64 65 70 40 100 87 84 88 90 90 95 80
class 3 70 75 75 90 100 80 55 65 76 80 88 99

a. find the mean, median, mode and range of class 1.
b. find the mean, median, mode and range of class 2.
c. find the mean, median, mode and range of class 3.
d. find the standard deviation of class 1.
e. find the standard deviation of class 2.
f. find the standard deviation of class 3.
g. which class had a higher standard deviation and what does that mean?
h. in your opinion, which class did better on the exam? explain your answer.