1. ## binomial

Many utilities companies have begun to promote energy conservation
by offering discount rates to customers who keep their energy usage below
certain established subsidy standards.A recent EPA report notes that
70% of residents in a community have reduced their electricity consumption
sufficiently to gualify for discount rates. Suppose 20 residential subscribers
are known to have randomly been selected from the community
a,Explain how the situation can be modeled by the Binomial distribution
b,Find the expected number of the residence who qualifies for the subsidy

Many utilities companies have begun to promote energy conservation
by offering discount rates to customers who keep their energy usage below
certain established subsidy standards.A recent EPA report notes that
70% of residents in a community have reduced their electricity consumption
sufficiently to gualify for discount rates. Suppose 20 residential subscribers
are known to have randomly been selected from the community
a,Explain how the situation can be modeled by the Binomial distribution
b,Find the expected number of the residence who qualifies for the subsidy
Let X be the random variable number of residents who qualify for discount rates.

X ~ Binomial (n = 20, p = 0.7)

You're left with the job of showing that the three key criteria for the validity of the binomial distribution are met. Reading this thread might help: http://www.mathhelpforum.com/math-he...ions-help.html.

E(X) = np = .....