Using the following 12 numbers (12, 34, 23, 10, 9, 45, 14, 34, 12, 13, 13, 35), calculate
1. the median
2. the mode
3. the mean
4. the 25th percentile, the 75th percentile
5. the variance
6. the standard deviation
7. the coefficient of variation
8. the range
9. the interquartile range.