00:01
40 % of low -income adults lost their jobs because of the coronavirus pandemic.
00:06
So for any given adult, p equals 0 .4.
00:11
And we're looking at a sample of n equals 10 adults.
00:15
So this is a binomial distribution.
00:18
And we want to use either the table or technology to find the probability of 0 in this sample, having lost their jobs, or one of this sample having lost their jobs, or so on.
00:31
I'll give you the formula that your technology is going to be using, which is a p equals n choose k, p to power of k, 1 minus p to power of n minus k.
00:44
A calculator can typically do this for you, and you just put in the parameters and it will spit out the answers.
00:53
So let's do that.
00:56
Make this formula small.
00:57
Or you can use a formula yourself, and you would just be putting these values in, and k would be the number of success.
01:03
So you have 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10.
01:17
So for 0, it's 1 times 1 times 0 .6 to the power of 10.
01:24
So that's 0 .0 .06.
01:28
And we want 4 decimal places, so 0 .0 .060.
01:36
For 1, we have 10 times 0 .4 times 0 .6 to power of 9, which is 0 .0 .0 .4 .0 .03 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .9.
01:56
9 .9.
02:03
9 .0 .9 .9.
02:06
And since it allows technology, let's just get the calculator to do for rest.
02:12
For three, it's 0 .215.
02:16
For 4, it's 0 .25.
02:24
5, it's 0 .207.
02:34
For 6, it's 0 .1115.
02:42
7, it's 0 .0 .042.
02:49
7, oh, oops, 0 .0, 4, 2, 5.
02:55
For 8, 0 .0106.
03:05
For 9, it's 0 ,016.
03:14
And for 10.
03:15
And at this point, it's just 0 .4 to power of 10.
03:18
It's 0 .010.
03:24
Okay, so that's part a and is just looking at a table or a calculator...