00:01
For this problem, we are told that scientists have devised an interesting way to measure a person's level of arsenic poisoning by examining toenail clippings.
00:10
We're told that in a recent study, nine scientists measured the level of arsenic in toenail clippings of eight people who lived near a former arsenic mine in great britain, and we're told that the following levels were recorded.
00:22
In part a, we are asked, do we expect the mean or the median of the toenail arsenic levels to be larger? and why.
00:31
So we can see, just looking at the data, that we have most of it is sort of clustered around the low end, and then we have two sort of outliers at the far high end.
00:44
So, one moment here, that would suggest a right - skewed distribution.
00:51
So right -skewed because high -end outliers, and that would then imply that the mean, or that we you'd expect the mean to be greater than the median.
01:02
Then for part b we're asked to calculate the mean and the median.
01:05
So we'll have that our sample mean x bar will be equal to the sum of the data points.
01:13
So i'll do that on screen here...