distribution
90–99: 1
80–89: 1
70–79: 2
60–69: 2
50–59: 1
descriptive statistics
arithmetic mean: 70.4285714285714
median: 70
standard deviation: 12.2046049076724
variance: 148.95238095238
kurtosis: -0.871723350187403
skewness: 0.717670709891185
range: 32
minimum: 58
maximum: 90
sample number: 7