00:01
Hey there, welcome to numerate.
00:03
We are looking at the weight of an adult poodle here, which follow a normal distribution, giving us a mean of 50 pounds, and a standard deviation that equals 15 pounds.
00:17
So what we're looking at here is a sample size of seven adult poodles, and we're asked to find a probability that the sample mean is between 45 and 55.
00:33
So with this, this is basically equivalent to the probability that the sample mean is less than 55 minus the probability that the sample mean is less than 45.
00:49
So we would have to find the probability of both of these scores here.
00:56
So let's set up disease scores.
00:58
We have 55 minus our population mean divided by our standard deviation divided by the square root of our sample size.
01:09
Giving us a z score here that equals around 0 .88.
01:16
Now we're going to find the z score for our other one here.
01:20
We have 45 minus 50 divided by 15 divided by 15 divided by the square root of 7.
01:30
So this should be the square root of seven actually, random sample of seven...