0:00
All right.
00:01
So for this problem, we're told that someone is claiming that the average cost to produce an event is equal to 80 ,000.
00:08
And we're trying to see with a sample of 28 whether or not this claim is true.
00:14
That means that our null hypothesis has to be that mu is equal to 80 ,000.
00:18
And that our alternative hypothesis is just that mu is not equal to 80 ,000.
00:26
This is because we're trying to disprove the claim that the average cost to produce an event is 80 ,000, but we're not specified in which direction.
00:37
So we are not given a greater than our less sense sign.
00:40
We're just taking a not equal to sign.
00:42
And so in order to actually evaluate this at the 5 % significance level, we need to calculate our t statistic, where t is equal to x bar minus u not divided by our sample standard deviation over the square root of n, which is going to be 83 ,000.
01:02
100 minus 80 ,000 divided by 500 over the square root of 28, which gives us a t statistic of 3 .3 .3 .32 .807.
01:38
This is a very large t statistic.
01:42
And so let's actually compare it with our t table here.
01:45
We are interested in, we're actually interested in a two -tail distribution because our alternative hypothesis is that mu is not equal to 80 ,000...