Question

this scatter plot shows the relationship between the age of a refrigerator and the amount of electricity the refrigerator
electricity used
each day (kwh/day)

based on the line of best fit of the data, which is the best prediction of the amount of electricity used each day by a re
old?
a. 1.75 kwh/day b. 2.25 kwh/day
c. 2.5 kwh/day d. 3.0 kwh/day

Explanation:

Step1: Analyze the line of best fit

The line of best fit in the scatter plot shows a positive linear relationship between the age of the refrigerator (x - axis) and electricity used (y - axis). Let's assume the refrigerator's age (though the exact age is missing, but we can analyze the options based on the line's trend). The line starts around (0,1) and has a slope. Let's check the y - values for typical x (age) values. For example, at x = 2, the line is around y = 1.5 - 2? Wait, no, looking at the plot, when x = 0, y = 1; at x = 2, y is around 1.5 - 2? Wait, no, the options are for a certain age (probably 3 - 4 years? Wait, the options are 1.75, 2.25, 2.5, 3.0. Let's see the line: at x = 3 (approximate), what's y? The line passes through points. Let's see the slope: from (0,1) to (10,4.5), the slope is (4.5 - 1)/10 = 0.35 per year. So for an age (let's say the refrigerator is around 3 - 4 years old? Wait, maybe the missing age is 3 years? Wait, let's check the options. Option B is 2.25, which is between 2 and 3. Wait, maybe the refrigerator is 3 years old. Let's calculate: y = 1+0.35x. If x = 3, y = 1 + 1.05 = 2.05, close to 2.25. Option A is 1.75 (too low), C is 2.5 (a bit high), D is 3 (too high). So the best prediction is 2.25.

Step2: Evaluate the options

• Option A: 1.75 is too low, as the line at a reasonable age (3 - 4 years) would be higher than 1.75.
• Option B: 2.25 fits the trend of the line of best fit. The line's slope and intercept suggest that for a typical age (maybe 3 - 4 years), the electricity used is around 2.25 kwh/day.
• Option C: 2.5 is a bit higher than what the line would predict for a moderate age.
• Option D: 3.0 is too high, as the line at x = 6 is around 3, so for a younger refrigerator (the age is probably less than 6, given the options), 3.0 is too much.

Answer:

B. 2.25 kwh/day