- (a) State one advantage and one disadvantage in using a census rather than a sample survey in statistical work.
(b) Give an example of a situation in which you would choose to use a census rather than a sample survey and explain why.
(2 marks) - An advert for Tatty's Crisps claims that 1 in 10 bags contain a free scratchcard game.
Tatty's Crisps can be bought in a Family Pack containing 10 bags. Find the probability that the bags in one of these Family Packs contain
(a) no scratchcards,
(b) more than 2 scratchcards.
Tatty's Crisps can also be bought wholesale in boxes containing 50 bags. A pub Landlord notices that her customers only found 2 scratchcards in the crisps from one of these boxes.
(c) Stating your hypotheses clearly, test at the \(10 \%\) level of significance whether or not this gives evidence of there being fewer free scratchcards than is claimed by the advert.
(4 marks)