The Number of Phone Calls Arriving at a Switchboard Each

question 55

Multiple Choice

The number of phone calls arriving at a switchboard each hour has been recorded, and the following frequency distribution has been developed.
$$\begin{array} { l c } \text { Class Interval } & \text { Frequency } \\20 \text {-under } 40 & 30 \\40 \text {-under } 60 & 45 \\60 \text {-under } 80 & 80 \\80 \text {-under } 100 & 45\end{array}$$
What is the relative frequency of the second class?

• A)0.455
• B)0.900
• C)0.225
• D)0.750
• E)0.725

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Definitions:

Stop Lights

Visual signaling devices at the rear of a vehicle designed to illuminate in red to indicate when the vehicle is braking.

Brake Pedal

A component in vehicles that the driver presses with their foot to activate the braking system, reducing or stopping vehicle movement.

DOT 3

A type of brake fluid specified by the Department of Transportation, characterized by its boiling point and chemical composition suitable for standard braking systems.

Rubber Master Cylinder Cap Seal

A rubber seal located on the cap of a master cylinder in a hydraulic system, designed to prevent leakage of brake fluid and contamination from entering.