How much does it cost to operate a clothes dryer rated at 6,700 watts for 6 hours at a utility rate of 10.09 cents per kW-hr?

To determine the cost of operating a clothes dryer rated at 6,700 watts for 6 hours at a utility rate of 10.09 cents per kW-hr, you first need to convert the wattage into kilowatts. Since 1 kilowatt equals 1,000 watts, the dryer consumes 6.7 kilowatts (6,700 watts ÷ 1,000).

Next, multiply the power consumption in kilowatts by the number of hours it operates:

6.7 kW * 6 hours = 40.2 kW-hr.

Then, multiply the total energy consumed by the cost per kilowatt-hour:

40.2 kW-hr * $0.1009 (10.09 cents converted to dollars) = $4.06.

This calculation shows that the correct answer is $4.06, reflecting the cost of using the clothes dryer under the given conditions. Understanding how to convert watts to kilowatts, calculate energy consumption, and apply the utility rate is crucial for accurately determining operational costs in electrical systems.