00:01
So you've produced a 95 % confidence interval for the preparedness of some college students and get the 58, 5 .8 to 7 .7.
00:09
And so we want to know in part a, what is the meaning of that confidence interval? and your meaning is going to be the one that is in your set, it's the second one that's listed.
00:21
And that is to say that, and let me quick get my, i have to find where my place is on your file, that a 95 % confidence interval has the property that if we repeatedly selected random samples exactly the same way, so exactly the same way, in other words, the same sample size, same way, each time we calculate and we construct that 95 % confidence interval, that 95 % of those intervals, 95 % of those intervals would contain the true mean, the true mean.
01:19
So that's the meaning, and i guess i said, i believe that's your second statement.
01:24
Now your second question, and let's change colors, is to look at if we perform a hypothesis test and we're doing a two -tail test and we get this p -value, what the meaning is of that p -value.
01:38
So when we say that the p -value is .03, what does that mean? so on the first one, it says, if the null hypothesis were true, then the true value of the parameter for the proportion who felt prepared is .03, that's absolutely wrong.
01:54
If the average college preparedness is really 5 .6, then we would expect to find sample results at least this extreme with a probability of .05...