00:02
In this video, we're going to use information about coyotes to determine whether or not we're going to accept or reject our null hypothesis.
00:12
And we are told that we have a sample size of 46.
00:17
The mean of our sample is 2 .05 years.
00:21
This is how long a coyote lives.
00:25
The standard deviation of our sample is 0 .82.
00:30
We know the mean of the population, so that's 1 .0 .8 .2.
00:33
We know the mean of the population.
00:33
And we are told that our significance level is 0 .01.
00:41
And then we're asked to see is the mean actually greater than 1 .75 years.
00:47
So in this particular situation, we need to state the null hypothesis.
00:56
So remember the null, nothing changes.
01:00
And then our alternative hypothesis will be 1 .75.
01:07
And then we need to determine which type of distribution we're going to do.
01:10
Be using and we will use this the student's t distribution because we don't know the standard deviation of the original population what we do know is the standard deviation of the sample so we're going to use the t distribution and then we're asked to actually calculate it so recall our formula for that is x bar minus mu over the standard deviation divided by the square root of n so when i plug those values in 2 .05 minus 1.
01:47
Divided by 0 .82 divided by the square root of 46.
01:53
Plug all those in and i will get a t value of approximately 2 .481.
02:02
Now i can do this with the calculator, but the calculator gives me a different estimate.
02:08
So i'm choosing to do this one by hand because it's not too hard to do this one by hand.
02:13
Now that i know that my t value, my test statistic is 2 .481, now i'm asked to find or estimate p.
02:24
Now, if i use my calculator immediately, i will know what p is.
02:28
But using my table, i need to go to table four.
02:31
I've copied part of it here.
02:33
I know that my degrees of freedom are 41 because remember, degrees of freedom, the sample size minus 1.
02:40
I said 41, i apologize, 45.
02:42
So my degrees of freedom are 45, so i need to come down my chart, find the row with 45 in it, and then my t value is 2 .481, and i can see that that will fall somewhere between these two numbers.
02:59
And now i know it's a one -tailed distribution, so here's my t value of 2 .481, and my p value will be somewhere in there.
03:15
And then i look between these two numbers and i can see that i have between 0 .010 and 0 .005...