Question

Lie Detector: Suppose a lie detector allows 20% of all lies to go undetected.

(a) If you take the test and tell 10 lies, what is the probability of having 4 or more go undetected? Round your answer to 3 decimal places.


(b) Would 4 undetected lies be an unusually high number* of undetected lies? Use the criteria that a number (x) is unusually large if P(x or more) ≤ 0.05.

Yes, that is an unusually high number of undetected lies. No, that is not an unusually high number of undetected lies.    

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*Unusually low and high number of successes:
x successes among n trials is an unusually high number of successes if P(x or more) ≤ 0.05.
x successes among n trials is an unusually low number of successes if P(x or fewer) ≤ 0.05.

Answer 1