Dale wants to save up some money to buy a new smartphone, so he babysits on the weekends. There is a proportional relationship between the time Dale spends babysitting (in hours), x, and the amount of money he earns babysitting (in dollars), y. What is the constant of proportionality? Write your answer as a whole number or decimal.
1 | $5
2 | $10
3 | $15
4 | $20
To find the constant of proportionality, calculate the ratio of y to x.
5 / 1 = 5
10 / 2 = 5
15 / 3 = 5
20 / 4 = 5
The ratio for each pair of x- and y-values is 5. So, the variables have a proportional relationship.
So, the constant of proportionality is 5 dollars per hour.