Assume that a given electronic device has a lifespan that is normally distributed with a mean of 10 years and a standard deviation of 2 years. According to the empirical rule, its manufacturer should issue a ______ warranty to ensure that no more than roughly 0.15% of buyers would be eligible for a free repair or replacement.

Why is it 4 years?

Question

Assume that a given electronic device has a lifespan that is normally distributed with a mean of 10 years and a standard deviation of 2 years. According to the empirical rule, its manufacturer should issue a ______ warranty to ensure that no more than roughly 0.15% of buyers would be eligible for a free repair or replacement.

Why is it 4 years?

miracrown · Answer

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when we say normally distributed, we mean a bell shaped curve like that, see?