Q1: Is the bottled water you're drinking really purified water? A four year study of bottled water brands conducted by the natural resources found that 25% if bottled water is just tap water. Consider a sample of five bottled water brands, and let x equal the number of these brands that use tap.
a) explain why x is (approx.) a binomial random variable
b) give the prob. distribution for x as a formula
c) find P(x=2)
d) find P(x<= 1)