Final answer:
To calculate the cost of operating a device, you need to know its power consumption and the cost of electricity per kilowatt-hour. You can use the formula: Cost = Power Consumption x Hours of Operation x Cost of Electricity.
Step-by-step explanation:
To calculate the cost of operating a device, you need to know the power consumption of the device and the cost of electricity per kilowatt-hour (kWh). In this case, the electric clock has a power consumption of 3.00 W and the cost of electricity is $0.0900 per kWh.
To calculate the cost, you can use the formula: Cost = Power Consumption (in kilowatts) x Hours of Operation x Cost of Electricity. First, convert the power consumption to kilowatts by dividing by 1000 (1 W = 0.001 kW). Then, multiply the power consumption, hours of operation (in this case, 24 hours/day x 365 days/year), and the cost of electricity to get the total cost.