Question

The table shows the temperature of an amount of water set on a stove to boil, recorded every half minute.

A 2-row table with 10 columns. The first row is labeled time (minutes) with entries 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4, 4.5. The second row is labeled temperature (degrees Celsius) with entries 75, 79, 83, 86, 89, 91, 93, 94, 95, 95.5.

According to the line of best fit, at what time will the temperature reach 100°C, the boiling point of water?

5
5.5
6
6.5

Answer 1

About 5 minutes.

Using linear regression on the data gives slope m ≈ 4.539 °C/min and intercept b ≈ 77.836. Solving 100 = m·t + b gives t ≈ (100−77.836)/4.539 ≈ 4.88 minutes, so about 5 minutes.