00:01
For this problem, to begin, we'd have that our null hypothesis is that the mean for the students who have taken this special preparation course is the same as the general population, 510.
00:15
The alternative hypothesis will be the claim that was made by the course, that is that the mean is greater than 510.
00:28
Now, we're told that an independent researcher takes a sample of 43 students, and let's see here.
00:39
Okay, interesting.
00:42
Oh, actually, no, never mind.
00:43
Not surprising.
00:44
The sample mean is equal to 512, and we are told that the population standard deviation is equal to 32.
00:57
We're asked to you, or to determine which are the type of test statistic to use.
01:03
Since we have a known population standard deviation and a fairly large sample, we'd use a z statistic for this test.
01:11
We're asked to find the value of the test statistic.
01:13
We do that by taking our sample mean minus the null hypothesized mean divided by the population standard deviation over the square root of the sample size.
01:27
So, plugging in our values and calculating that out, we'd have, pardon me, not 43, it would be 512 minus 510, divided by 32 over the square root of 43.
01:39
So we get a test statistic equal to 0 .4098, roughly.
01:47
Whereas for the p value, the p value is just going to be the probability of getting a test statistic greater than or equal to our observed value, which i'm going to round for the purposes here as 0 .41, just because my table that i'll be using only has two decimal places on it...