For a left skewed shape, the mean is typically less than the median. Also, the median is closer to the third quartile than to the first quartile
For a right skewed shape, the mean is typically greater than the median.
The first step is to determine the mean of the data set
Mean = (60 + 68 + 70 + 72 + 80 + 84 + 85 + 90 + 90 + 92 + 92 + 94 + 94 + 94 + 96 + 96 + 98 + 100)/18
Mean = 1463/18 = 81.3
Median = (90 + 92)/2 = 91
We can see that the mean is less than the median
We can go further by determining the first and third quartile
First quartile = 80
Third quartile = 94
The median is slightly closer to the third quartile than the first quartile.
Thus, the data set is left skewed