Question

A pet store owner surveys 100 customers to find out what brand of dog food is purchased most frequently.
a. population: 100 customers

sample: dog food brand

possible bias: not all customers buy that particular dog food brand c. population: pet store customers

sample: 100 customers

possible bias: not all customers have dogs
b. population: 100 customers

sample: pet store customers

possible bias: not all customers shop at the pet store d. population: pet store customers

sample: 100 customers

possible bias: not all customers have pets