Question

The graph represents the function where electricity usage in kilowatts per hour of a clock radio varies directly with the number of days it is plugged into the wall current. A coordinate grid showing Clock Radio Electricity Usage, with Days Connected to Current on the x-axis and Electricity Usage in kilowatt-hours on the y-axis with a line starting at (0, 0) and passing through (2, 0.5) and (6, 1.5).

Which is a reasonable estimate of the constant of variation?
A. 0.25 kWh per day
B. 0.50 kWh per day
C. 2.40 kWh per day
D. 4.00 kWh per day

Answer 1

Option,A

Explanation:

Answer 2

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:

`\displaystyle(y_2-y_1)/(x_2-x_1)`

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

`\displaystyle(1.5-0.5)/(6-2) = (1)/(4) = 0.25\text{ kilowatt-hours per day}`

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