If X, the Time (In Minutes)to Complete an Oil Change $\le$

question 66

Multiple Choice

If x, the time (in minutes) to complete an oil change job at certain auto service station, is uniformly distributed over the interval 20 to 30, inclusively (20 $\le$ x $\le$ 30) , then the standard deviation of this distribution is __________________.

• A)unknown
• B)8.33
• C)0.833
• D)2.89
• E)1.89

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Definitions:

Hearing-Impaired

A term used to describe individuals who have partial or total inability to hear sounds.

Lip Reads

The process of understanding speech by visually interpreting the movements of the lips, face, and tongue, used especially by those with hearing impairments.

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The act of making sounds or articulation of words more pronounced than usual, often for emphasis or effect.

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A genetic disorder caused by the presence of all or part of a third copy of chromosome 21, characterized by developmental and intellectual delays.