Question

A student in a Grade 9 math class has recorded the following data from observing a burning candle that his parent lit during the holiday season. The candle is 21 cm long with a diameter of 2 cm. Time (min) Height (cm) O 21 2 4 6 8 19.5 18 16.5 15

Answer 1

Using Excel,

25 Time (min) 0 Height(min) 21 19.5 y = -0.75x + 21 2. 20 4 18 6 16.5 8 15 Height (min) 5 0 0 2 4 6 8 10 Time (min)

From the graph and linear equation we can say it is partial variation. Since, graph passes through y axis and not from origin. In other words, the linear equation has y-intercept. so it is partial variation example.