00:01
We have some information about statistics students.
00:04
I'm going to make a table of this data.
00:06
So men and women, a or not a.
00:13
So, there are 18 men and 13 women.
00:19
So it gives us a total of 31 students.
00:22
And four of the men received an a, five of a women received an a.
00:28
Which leaves 14 men who didn't, and eight women who didn't.
00:33
That's 9 a's in the class, and 22 something else.
00:39
So filling out this table is going to make this a little easier for us.
00:44
Part a, what is the probability that a randomly selected student is a woman? so all we need to do is make a fraction where we have the number of people who meet this criteria out of the total number.
00:59
So that's 13 out of 31.
01:02
Or as a probability, 13 divided by 31, is 0 .4194 to four decimal places.
01:16
Up b, we want the probability that they received an a.
01:24
So that's nine students out of 31.
01:32
9 divided by 31 is 0 .2903.
01:38
See? probability, they are a woman or received an a.
01:48
This symbol here is union.
01:50
It means this or that or both...