A company wants to know the most popular brand of water brought by customers that are 20 to 25 years old in Texas. Which sampling method produces an unbiased, representative sample of the population?
a Randomly survey 400 retired doctors in Texas.
b Survey the first 250 people in the 20- to 25- age range the statistician from the company comes across at a fitness event in North Carolina
c Survey every 3rd customer in the 20-25-year-old age range that buys water at a randomly selected grocery store in Texas.
d Survey the first 100 customers at a randomly selected grocery store in Maine.
