Alocal dairy conducted taste tests of their nonfat and low fat cream cheese spreads at three supermarkets on one saturday. they asked people to compare a cracker with their low fat spread on it and another cracker with the nationally known brand of the same type of spread.

at one supermarket, everyone who came to the testing table, located just inside by the front door, and asked to participate was included. at a second market, only people who appeared to be older teenagers and adults were allowed to participate. the testing table was in the section of the store where paper goods are sold. at the third store, the testing table was in the dairy section and everyone who was asked to participate was included. however, they ran out of one of the products and had to stop the test three hours earlier than they planned.

the table below shows how many people were tested at each location and their stated preferences

store a
number tasters = 258
number preferring local brand = 167
store b
number tasters = 315
number preferring local brand = 151
store c
number tasters = 152
number preferring local brand = 90
a: did this taste test use random sampling? in two or more complete sentences, justify your answer based on facts provided in the description and your understanding of random sampling.
b: calculate the proportion of tasters who preferred each option at each location. include estimates for store a, store b, and store c.