A shipment contains 20 assembled circuit boards of which five are defective. Ten circuit boards from the shipment are selected without replacement. Suppose that X denotes the number of defective boards out of the 10 selected. Find the probability distribution of the random variable X and then find its mean and variance.
x 0 1 2 3 4 5
p(x)____
Mean, μ=___
Variance, σ²=____