00:01
For this problem, we got data from a previous problem, and the data included 16, 5, 21, 19, 10, 5, 8, 2, 7, and 2, 4, 9.
00:19
And these happened to be lc50 measurements in terms of parts per million of a certain species of fish.
00:36
And we're trying to determine whether this provides sufficient evidence that is going to indicate that the average is less than six.
00:49
So in order to do that, we will need to run a hypothesis test, which requires us to determine a null and alternative hypothesis.
01:00
The null hypothesis is always going to be a statement of equality.
01:05
And since this is a statement of inequality, it will be our alternative hypothesis.
01:11
The complement to that is going to be that mu is equal to six.
01:17
So since our alternative hypothesis had a less than symbol, we will be running a left -tailed test.
01:25
And this boundary line is going to separate the curve into two regions, the fail to reject region and the reject region.
01:44
And we need to determine the critical number that separates the two.
01:50
Now because we have a small sample size, we will be running a t test.
01:56
So we will need a standardized test statistic.
02:05
And in order to find that standardized test statistic, we will apply the formula t equals y bar minus mu over s over the square root of n.
02:19
So that means we need to go to our data and gather some information.
02:25
We can count that n is equivalent to 12.
02:29
We have to determine the average and the standard deviation.
02:34
So in order to do that, i'm going to bring in my graphing calculator, and i've taken the opportunity already to hit my stat button and edit and place the data into my calculator.
02:47
So i'm now going to run one variable statistics on that data by hitting stat, moving over to the calculate menu, one variable statistics on everything i stored in list one...