The graph shows a proportional relationship between the number of books sold at a yard sale and the amount of money collected from book sales. What is the constant of proportionality?

The constant of proportionality is 1.5
The constant of proportionality is the ratio of two proportional values at a constant value. Two variable values have a proportional relationship when either their ratio or their product gives a constant. The proportionality constant's value is determined by the proportion between the two specified quantities
The constant of proportionality k is given by k=y/x where y and x are two quantities that are directly proportional to each other. Once you know the constant of proportionality you can find an equation representing the directly proportional relationship between x and y, namely y=kx, with your specific k
For example, we could use y = price in dollars, x = gas in gallons, and a constant of proportionality k to represent the amount of money you have to pay at the gas station: y = kx. In other words, the price you pay is in direct proportion to the gallons pumped.
Learn more about constant of proportionality, refer
https://brainly.com/question/11804610
#SPJ2