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mean = 1*0.5+2*0.3+3*0.2=1.7now calculte the expected x^21^2*0.5+2^2*0.3+3^2*0.2=3.5hence the standard deviation is:stdev = sqrt(3.5-1.7^2)=0.781

Answer: mean = 1.7, standard deviation = 0.781

Not understanding the second half of the answer.

ok

to get the standard deviation

you need to calculate the variance first

recall that variance is defined as a difference between the mean of the squares: 1,4,9

and the square of the mean 1.7

the mean of the squares is found to be 3.5

and the variance is hence 3.5-1.7^2 = 0.61

now taking the square root of this we get standard deviation = √0.61 =0.781

is it clear now?

I am trying to understand is (1)^2(0.5) or (1)(0.5)^2?

I have to show all of my steps

it is one squared times point five

because you need he mean of the squares

the numbers you have are 1,2,3 so the squares are 1, 4, 9

hence 1*0.5+4*0.3+9*0.2=3.5

does it make sense now?

yes

OK, good