Question

A group of friends wanted to compare their average running speeds. They recorded the distance and amount of time each person ran one Saturday morning.
Select all the runners whose speeds are in a proportional relationship with each other.

Answer 1

Answer with explanation:

Since there is no information provided on what options to determine the proportional relationship, so I will be demonstrating using examples and telling the method to compare the average running speeds.

Consider a group of 3 friends named Charles, Beck and Anna.

As they wanted to compare their average running speeds, they recorded the distance and amount of time each person ran one saturday morning.

To calculate Average Speed, we use:

Average Speed = $\frac{Distance}{Time}$

Example:

Charles Ran:

5 km in 30 minutes

Beck Ran :

2 km in 25 minutes

Anna Ran:  

4 km in 20 minutes

Average speed of Charles = $\frac{5(1000)}{30(60)}= 2.78 m/s$

Average speed of Beck = $\frac{2(1000)}{25(60)}= 1.33m/s$

Average speed of Anna = $\frac{4(1000)}{20(60)}= 3.33m/s$

Here, we can see from comparison that Average running speed of Anna is the most.

Speed of Beck is proportional to both Charles and Anna.

Charles' Speed =2 (Beck's Speed)

Anna's Speed =2.5 (Beck's Speed)