Use the Empirical Rule to Solve the Problem

question 28

Multiple Choice

Use the empirical rule to solve the problem.
-The lifetimes of lightbulbs of a particular type are normally distributed with a mean of 400 hours and a standard deviation of 12 hours. What percentage of the bulbs have lifetimes that lie within 2 Standard deviations to either side of the mean?

• A)97.72%
• B)99.74%
• C)95.44%
• D)68.26%

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Definitions:

Capacitive Reactance

The opposition that capacitors present to the change of voltage in AC circuits, inversely related to the frequency of the current and the capacitance.

Parallel Connection

A way of connecting electrical components in a circuit side by side, so each component is directly connected to the voltage source, and the voltage is the same across all components.

Frequency Source

A device or component that generates a steady and specific frequency of electrical signal.

Capacitive Reactance

The opposition that a capacitor presents to the change in voltage, measured in ohms.