00:01
For this question, let's start by just finding a z -score.
00:05
So, um, if we have a standard deviation of 1 .16, a mean of 3 .36, uh, that was a standard deviation of the sample, so s.
00:26
And, um, we did a sample of 28 houses, and we found that the mean number of residents was 2 .74.
00:37
We wanna see if the mean is less than or not less than the, um, 3 .36.
00:55
So our null hypothesis is gonna be that the mean is equal to 3 .36.
01:06
The alternative hypothesis is gonna be that the mean is greater than 3 .36, because, sorry, we're trying to see that it's less than.
01:16
Yeah, so it's gonna be less than.
01:22
Okay, so let's find our z.
01:23
So it's gonna be 3 .36 minus, um, our sample mean, 2 .74, over standard deviation, 1 .16, over square root of n, 28.
01:40
So we're gonna plug it in the calculator, 1 .16 divided by square root of 28, 0 .2192.
01:54
Up top, we have 3 .36 minus 2 .74, 0 .62, divided by 0 .2192, 2 .83.
02:09
That's gonna be our z score.
02:12
Now, at a 0 .1 significance level, alpha is gonna be 0 .05, because this is gonna be, oh, i'm sorry.
02:24
No, this is actually gonna be one -tailed...