Which one is the correct statement? Choose all applied.
a. If you are interested in US households, proportion of 500 US households who do not have any health insurance is a point estimate of proportion of all US households who do not have any health insurance.
b. If you are interested in US households, mean income of 500 US households is a random variable.
c. If you are interested in US households, mean income of 500 US households is a point estimate of mean income of all US households.
d. If you are interested in US households, mean income of US households is a fixed number, that is, not a random variable.