A pollster conducts a survey by phone. The probability that a call does not result in a person taking this survey is 85%. What is the probability that the pollster makes 4 calls and none result in a person taking this survey?
.85^4
How do you know to do that operation?
Update ?
To find the probability that the pollster makes 4 calls and none result in a person taking the survey, we can use the concept of independent events.
Since each call has a 85% probability of not resulting in a person taking the survey, the probability of a call resulting in a person taking the survey is 1 - 0.85 = 0.15.
Now, let's calculate the probability of making 4 calls and none resulting in a person taking the survey. Since these events are independent, we can multiply the probabilities together.
P(4 calls with no survey) = P(no survey on 1st call) * P(no survey on 2nd call) * P(no survey on 3rd call) * P(no survey on 4th call)
P(4 calls with no survey) = 0.85 * 0.85 * 0.85 * 0.85
P(4 calls with no survey) = 0.52200625
Therefore, the probability that the pollster makes 4 calls and none result in a person taking the survey is approximately 0.522 or 52.2%.