(co 4) forty-nine percent of us teens have heard of a fax machine. you randomly select 12 us teens. find the probability that the number of these selected teens that have heard of a fax machine is exactly six (first answer listed below). find the probability that the number is more than 8 (second answer listed below).

Forty-nine percent of US teens have heard of a fax machine, then the probability that the teen has heard of a tax machine is p=0.49 and the probability that the tenn hasn't heard of a tax machine is q=1-p=1-0.49=0.51.

Use binomial distribution.

The probability that among 12 randomly selected teens exactly 6 have heard of a fax machine is

The probability that among 12 randomly selected teens more than 8 have heard of a fax machine is

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