Mean Deviation about Median

Q. State whether $2x^2-6x+\frac{9}{2}=0$ has two distinct real roots. Justify your answer.

Q. If the median and mode of 4 observations is 4, 6 and the sum of squares of observations is 48. Then
standard deviation is

1. 4
2. 
3. 
4. 

Q. Find the mean derivation from the mean for the following data

$x_1$	$2$	$5$	$6$	$8$	$10$	$12$
$y_1$	$2$	$8$	$10$	$7$	$8$	$5$