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About 40% of all drivers will flash their lights to warn oncoming traffic of a speed trap ahead. suppose seven cars have just driven past a police speed trap.
a. what is the probability that at least one of the drivers will warn oncoming traffic?
b. what is the expected number of these seven drivers who will warn oncoming traffic of a police speed trap ahead? what is the standard deviation?

Respuesta :

a. The probability of none of the 7 drivers flashing their lights is (1-0.4)⁷=0.028 approx. So the probability of at least one flashing their lights is 1-0.028=0.972 or 97.2%.

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