00:01
All right, we're given that the proportion of individuals who are insured under a certain insurance company get at least one traffic ticket is 0 .15, so 15%.
00:16
So for part a, it wants us to draw a sampling distribution graph for n equals 150.
00:23
So first off, let's check if we can use a normal distribution to approximate this.
00:29
So at n times p, we check with that.
00:34
So let's first check n times p, which is 22 .5, which is greater than five.
00:41
So we're good.
00:46
And then n times 1 minus p, that's 150 times .85, which is 127 .5, which is also definitely greater than five.
00:55
So we are good to use a normal distribution.
01:00
So let's just sketch this out.
01:10
Not the nicest looking normal curve, but it's close enough, i guess.
01:15
Anyway, first off, let's find our mean for p hat, or not p hat, p bar.
01:24
Some other sources use p hat.
01:28
But that's besides the point, that's just going to equal population.
01:34
So that's 0 .15.
01:37
Standard deviation of p bar.
01:40
It's just p times one minus.
01:43
Whoa, hello.
01:43
So that was weird.
01:47
1 minus p, all over n, take the square root of it.
01:54
When you multiply that out, sorry about that.
02:02
When you multiply that out, you get approximately 0 .029.
02:13
Okay, knowing this, let's get a sketch of what our graph looks like.
02:21
All right, so this mean, it's going to be 0 .15.
02:26
And then this can be 0 .179 and 0 .1211.
02:42
Yes...