If Q means 'add to', J means 'multiplied by', T means 'subtract from' and K means 'divide by', then 30 K 2 Q 3 J 6 T 5 = ?
Let the Mean and Variance of five observations $ x_i $, $ i = 1, 2, 3, 4, 5 $ be 5 and 10 respectively. If three observations are $ x_1 = 1, x_2 = 3, x_3 = a $ and $ x_4 = 7, x_5 = b $ with $ a>b $, then the Variance of the observations $ n + x_n $ for $ n = 1, 2, 3, 4, 5 $ is
Find the variance of the following frequency distribution:
| Class Interval | ||||
| 0--4 | 4--8 | 8--12 | 12--16 | |
| Frequency | 1 | 2 | 2 | 1 |
Find the letter to be placed in '?' 
What is 'X' in the following table?
Find the missing number from the given options: 