Paradise Real-estate developer is considering building a condominium project. Five different sizes are being considered. The probabilities reflect the company's belief that the profit will be realized (e.g., there is a 20% chance that a $4.2 million profit will result if the 30 unit condominium is built).

Condominium size	Probability	Net Profit (Millions $)
10 units	0.1	2.1
20 units	0.3	3.5
30 units	0.2	4.2
40 units	0.05	4.4
50 units	0.35	5.9

What is the standard deviation for expected profit?

a. 1.2519

b. 1.5673

c. 2.4564

d. 1.4321