Consider the following to answer the question(s) below:
An airline has found that its flights between Toronto and Vancouver can take anywhere from 4.5 - 7.5 hours, with any time between this range being equally likely.
-What is the standard deviation?
A) 0.75 hours
B) 0.87 hours
C) 6 hours
D) 0.33 hours
E) The standard deviation cannot be determined.

Question

Quizplus · Accepted Answer

The range of possible flight times is 7.5-4.5=3 hours. The midpoint is (7.5+4.5)/2=6 hours. We can use the formula for standard deviation, sigma, which is given by: sigma=sqrt((b-a)^2/12), where a is the lower limit, b is the upper limit, and sqrt means "square root". Plugging in the values we get: sigma=sqrt((7.5-4.5)^2/12)=sqrt(3^2/4)=sqrt(9/4)=0.75. Therefore, the standard deviation is 0.75 hours, which corresponds to choice B.

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