If Light Bulbs Have Lives That Are Normally Distributed with a Mean

question 36

Multiple Choice

If light bulbs have lives that are normally distributed with a mean of 2500 hours and a standard deviation of 500 hours, use the 68-95-99.7 rule to approximate the percentage of light bulbs having a life between 2000 hours and 3500 hours?

• A) About 13.5%
• B) About 50%
• C) About 68%
• D) About 81.5%

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Definitions:

Limiting Factor

A factor in the environment that restricts the development, quantity, or spread of a species or a group of species within an ecosystem.

Desert

A barren area of landscape where little precipitation occurs and consequently living conditions are hostile for plant and animal life.

Arctic Tundra

A biome characterized by cold, desert-like conditions, found in the Arctic regions, supporting a limited range of plants and animals adapted to extreme cold.

Global Air Circulation

The large-scale movement of air through the earth's atmosphere, distributing heat and moisture around the planet.