Recent content by badgerbadger

suppose that X is normally distributed with mean u and standard deviation sigma. show that var(x)=sigma^2.[you many use the fact that if Z is standard normally distributed, then EZ=0 and var(x)=1]

suppose that f(x) is the density function of a normal distribution with mean u and standard deviation sigma. show that u= intergral from -infinity->+infinity xf(x)dx

That it is possible to place either a positive or a negative charge between the other two positive charges. the actual value of the unknown charge cancels out of the equation, but I am not sure why a negative charge can not be placed somewhere between the two positive charges.

Homework Statement Two small beads having positive charges 3q and q are fixed at the opposite ends of a horizontal, insulating rod, extending from the origin to the point x=d. A third small charged bead is free to slide on the rod. At what position is the third bead in equilibrium? What type...

haha yeah its f(x)= 0.5e^{-|x|} sorry about that.

Let X be a continuous random variable with density function f(x)= .5e^|x| for x range R. Find EX and Var(x) help please!

Let X be a continuous random variable with P(X>x)=e^-ax, x less/equal 0 Where a is a positive constant. Find EX and Var(x)