Answer:
Reasonable estimation for constant of variation is 0.25 kWh per day.
Explanation:
We are given the following information in the question:
- The graph represents the function where electricity usage.
- Electricity usage in kilowatts per hour of a clock radio varies directly with the number of days.
- The x-axis shows the number of days and usage in kilo-watt per hour is showed on the y-axis.
- Some coordinates of the graph are: (0,0), (2,0.5) and (6,1.5)
Formula for constant of variation:

Putting the values from the coordinates (2,0.5) and (6,1.5), we get:

Hence, reasonable estimation for constant of variation is 0.25 kWh per day.