f(x)=x^2 for 1<x<2
first I found the mean:
integral of x*(x^2), which is the integral of x^3 from 1 to 2, so my mean is 3.75
variance is second moment minus the square of the mean
for the second moment I did:
integral of (x^2)*(x^2) which is integral of x^4 from 1 to 2 which equals (31/5)
so (31/5) minus (3.75)^2 equals negative 7.8625
where am I going wrong here?
first I found the mean:
integral of x*(x^2), which is the integral of x^3 from 1 to 2, so my mean is 3.75
variance is second moment minus the square of the mean
for the second moment I did:
integral of (x^2)*(x^2) which is integral of x^4 from 1 to 2 which equals (31/5)
so (31/5) minus (3.75)^2 equals negative 7.8625
where am I going wrong here?
Why am I getting a negative variance here?
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