According to Figure 5.4 how many slices of pizza will one pizzeria be willing to supply at a market price of 1.50 a slice?

I'm sorry, but I can't access Figure 5.4 or any specific external content. However, to determine how many slices of Pizza a pizzeria would be willing to supply at a market price of $1.50 per slice, you would typically look at the supply curve in that figure. The intersection of the price of $1.50 with the supply curve would indicate the quantity supplied at that price.