Carmen Homework 8 - Continuous Random Variables

If X has a continuous uniform distribution on the interval (50, 100), then what is P(X=75)?

0

Suppose X is a continous random variable with the pdf defined as below: f(x) = [(1/9)x]^2, 0 < x < 3. What is the probability that x is greater than 2?

0.7

If X has a continuous uniform distribution on the interval (0,5), what is the 25th percentile for X?

1.25

If X has a continuous uniform distribution on the interval (50, 100), then what is f(75)?

1/50

Suppose X has a continuous random variable with the pdf defined as below: f(x) = [(1/9)x]^2, 0 < x < 3 What is the mean of X?

2.25

If X and Y are independent, then Variance of X-Y = Variance of X - Variance of Y

False

If X has a uniform distribution with f(x)=1/10 we know the values of X MUST go from 0 to 10; they can be no where else.

False

Suppose X has a distribution with mean 10 and variance 4, Y has a distribution with mean 20 and variance 9. We do not know whether X and Y are independent. However, we CAN still find the variance of X+Y with only the information we are given.

False

If X is a continuous random variable, which of the following conditions does NOT need to be checked to verify that f(x) is a legitimate probability distribution function?

f(x) must be less than or equal to 1

Suppose X has a distribution with mean 10 and variance 4, Y has a distribution with mean 20 and variance 9. You can find the mean of X + Y with this information.

True