00:01
So we have a mean cost from going from a beach to the la airport, i believe it was, was $18 with a standard deviation of $3 .50.
00:13
And they say we're taking a random sample of 15 fares.
00:19
And we want to know in part a, what's the likelihood that that mean would be between $17 and $20.
00:28
Let's assume it's inclusive.
00:31
Then they ask in part b, what assumptions are we making with part one? well, this is a small sample size and the shape is unknown to us.
00:42
So we do know the standard deviation.
00:45
So we would be making the assumption that our distribution is approximately normal.
00:52
Because otherwise, if we don't know the shape of this distribution and this sample size is relatively small, our central limit theorem is not going to tell us the information that we're quite sure it's normal.
01:04
So if this had been a sample size of 30 or higher, then i wouldn't care about the shape of this distribution when referring to a sample...