00:01
So for this problem, focusing first on setting up the contingency table, i'll just get that, actually, i'll just type this up here.
00:09
So we know that the different possibilities are that somebody has a 401k.
00:14
So we have 401k and no 401k is our two possibilities across the top.
00:20
And then we want to have a column for the total.
00:24
And i'll put another column to the left because then we need to have the i.
00:30
Ira and no ira and a total row.
00:37
So for drawing out the full contingency table with the information that we're given, we're told that there is a, that the probability of somebody having a 401k overall is equal to 0 .43.
00:51
So that would go into this cell right here.
00:55
The total probability of a 401k is 0 .4, or 0 .43, which then by extension means the probability of of not having a 401k, 1 minus 0 .43, for a result of 0 .57.
01:12
And as expected, we should total up to 1.
01:15
Then we're told that the probability of a roth ira is equal to 0 .179...