Calculation of Standard deviation and expected return

State	P	return (x)	expected return(P*X)	d = (X -10.5)	d^2	pd^2
Boom	0.1	25	2.50	14.50	210.25	21.03
Good	0.4	15	6.00	4.50	20.25	8.10
Level	0.3	10	3.00	-0.50	0.25	0.08
Slump	0.2	-5	-1.00	-15.50	240.25	48.05
			10.50			77.25
Expected return	10.50
Standard deviation	sqrt of 77.25	8.79

WHAT CALCULATION WAS USED TO GET THE LAST ROW OF NUMBERS P^2, I KNOW THE SUM 77.25 WAS FROM ADDING THE NUMBERS IN THE LAST ROW, BUT I DONT UNDERSTAND WHERE THOSE NUMBERS CAME FROM. THE 21.03, 8.10 ETC. THAT WHOLE ROW. CAN YOU PLEASE SHOW ME HOW THE CALCULATION