In Seattle the temperature dropped - 15.5 degrees in 2.5 hours. The temperature fell at a constant rate. How much did the temperature change in the first hour?

In the first hour the temperature dropped - 6.2 degrees.

Step-by-step explanation:

To solve this question, we can use the rule of three. This mathematical rule is used to solve problems with proportions. To use it we must have three numbers. In this case we have: the temperature (-15.5°) and two-time data (2.5 hours and 1 hour). So, we solve the problem in this way:

In 2.5 hours - -> the temperature dropped - 15.5°

In 1 hour <- - how did the temp. change?

We first multiply:

1hour*-15.5° = - 15.5° hours * degrees

Then we divide:

-15.5 hours * degrees / 2.5 hours = - 6.2 degrees (because hours in the numerator eliminates hours in the denominator)

Then, in 1 hour the temperature dropped - 6.2 degrees.