1. The sum of 10 items is 12 and the sum of their squares is 18. The standard deviation is

2. The algebraic sum of the deviation of 20 observations measured from 30 is 2. So, the mean of observations is

3. The coefficient of variation is computed by

4. When tested the lives (in hours) of 5 bulbs were noted as follows: 1357, 1090, 1666, 1494, 1623. The mean of the lives of 5 bulbs is

5. If mode of a series exceeds its mean by 12, then mode exceeds the median by

6. The median and SD of a distributed are 20 and 4 respectively. If each item is increased by 2, the new median and SD are

7. Range of the data 4, 7, 8, 9, 10, 12, 13 and 17 is

8. If Mean = Median = Mode, then it is

9. If the difference of mode and median of a data is 24, then the difference of median and mean is

10. If r is the correlation coefficient, then