Math
posted by Jen on .
Mr. Doodle’s grade distribution over the past 3 years for a course in college algebra is shown in the chart below.
Grade Number
A 45
B 180
C 110
D 95
F 65
I 5
If Jane plans to take a college algebra course with Mr. Doodle, determine the empirical probability that she receives at least a B. I think it's 1.7777 ??

Since when can a probabliity be greater then one?

is it 180/500 = 2.7777???

Jen, think. How can 180/500 be more than one.

Jen!! 2.777 is also greater than one!

Prob of at least B is = prob of A +prob of B= (45+180)/totalofallgrades

oooooooh i totally messed up!!! sorry i did 500/180 instead of 180/500....so it would be 0.36....sorry :(

No.
You forgot to include the A grades.
Bobpursley explained that above. 
225/500 = 0.45??

Right.

great! i get it...thank u :)

the answer would be D 95