00:01
This problem says the links in centimeters of a sample of nine otters measured to the nearest centimeter by a wildlife research team are given, and we want to calculate the mean and stern deviation of the nine recorded links.
00:12
And this is a sample, so we're looking for the sample mean in sample standard deviation.
00:16
And the sample mean will be found from taking the sum of all of our observations and dividing by the number of observations we have.
00:22
And when we sum all of our values up, we get the result of 696, and we would divide that by nine, and rounded it.
00:30
To two decimal places that would give us a mean of 77 .33.
00:37
And we'll need that mean for the sample standard deviation because the sample standard deviation is found from the square root of the sum of all of our observations minus the mean squared and then divided by n minus one or the number of observations we have minus one.
00:54
So in our case we will take every observation, starting with 76, and subtracting.
01:00
77 .33 and square it.
01:03
And then we will add the next observation again subtracting 77 .33 the mean and then squaring and we'll continue our line below where we next have 91 minus 77 .33 squared and then plus the next observation which would be 65 minus our mean squared.
01:28
Next we'll have 63...