A) Just before a referendum on a school budget, a local newspaper polls voters t

ID: 3226033 • Letter: A

Question

A) Just before a referendum on a school budget, a local newspaper polls

voters to predict whether the budget will pass. Suppose the budget has the support of

of the voters. What is the probability that the newspaper's sample will lead it to predict defeat? round to the nearest three decimal places.

B) A new restaurant with

seats is being planned. Studies show that

of the customers demand a smoke-free area. How many seats should be in the non-smoking area in order to be very sure

of having enough seating there?

a) here p=0.53 and n=373

hence std error of proportion =(p(1-p)/n)1/2 =0.0258

hence probability that the newspaper's sample will lead it to predict defeat=P(P<0.5)

=P(Z<(0.5-0.53)/0.0258)=P(Z<-1.1609)=0.1228

B) for mean =np=149*0.61=90.89

std deviation =(np(1-p))1/2 =5.9537

hence

seats should be in the non-smoking area in order to be very sure of having enough seating there

=+3 =90.89+3*5.9537=~109(rounding it up)

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