Question

Help please

Lindiwe suspected that the relationship between temperature and electricity consumption is not linear for all temperatures. She collected data for peak temperatures down to 0°C as shown in the graph.

Which of the following projections is MOST accurate?

A.
When the peak temperature is 40°C, 35 units of electricity are used on average.

B.
When the peak temperature is 40°C, 72 units of electricity are used on average.

C.
When the peak temperature is 40°C, 48 units of electricity are used on average.

D.
When the peak temperature is 40°C, 120 units of electricity are used on average.

Answer 1

• B. When the peak temperature is 40°C, 72 units of electricity are used on average.

Explanation:

We see the relationship is closer to linear in the interval 30 to 40

Approximate points:

• (30, 34) and (34, 54)

The slope of the line:

• m = (54 - 34)/(34- 30) = 20/4 = 5

The line is:

• y - 34 = 5(x - 30)
• y = 5x - 116

At x = 40, the value of y would be:

• y = 5*40 - 116 = 84

The closet option is B