Determine if the outcome is unusual. Consider as unusual any result that differs from the mean by more than 2 standard
deviations. That is, unusual values are either less than $\mu - 2 \sigma$ or greater than $\mu + 2 \sigma$
-The Acme Candy Company claims that 8% of the jawbreakers it produces actually result in a broken jaw. Suppose 9571 persons are selected at random from those who have eaten a jawbreaker produced at Acme
Candy Company. Would it be unusual for this sample of 9571 to contain 801 persons with broken jaws?
A) Yes
B) No

Question

Quizplus · Accepted Answer

The expected number of persons with broken jaws in a sample of 9571 can be calculated by:
Expected value = (8/100) x 9571 = 765.68

The standard deviation can be calculated by:
sqrt(npq) = sqrt(9571 x 0.08 x 0.92) = 27.84

Therefore, the range of unusual values would be:
Less than μ - 2σ = 765.68 - 2(27.84) = 709
Greater than μ + 2σ = 765.68 + 2(27.84) = 822.36

Since 801 falls within this range, it would not be considered an unusual outcome. Therefore, the answer is B.

Determine If the Outcome Is Unusual μ−2σ\mu - 2 \sigmaμ−2σ Or Greater Than

Determine If the Outcome Is Unusual $\mu - 2 \sigma$ Or Greater Than