<PRE><B>Question 1147643</B>
The z-score associated with a probability of 0.07 is -1.47
:
Note use table of z-scores to lookup probabilities
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(X - 3.3)/0.5 = -1.47
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X - 3.3 = −0.735
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X = 2.565 is approximately 3
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Therefore, we can expect 3 items have shortest lifespan represent 7% of all items 
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