A manufacturing company finds that they can sell 125 items at $2.50 per item and 375 items at $1.50 per item.
If the relationship between the number of items sold z and the price per item p is a linear one:

Find a formula that gives z in terms of p: x =___

Now use the formula to find the number of items they will sell if the price per item is $2.00. They will sell ____ items if the price is $2.00.