Which of the following is not true of a demand curve?
a. it has negative slope.
b. it shows the amount consumers are willing and able to purchase at various prices, holding other factors constant.
c. it relates the price of an item to the quantity demanded of that item.
d. it shows how an increase in price leads to an increase in quantity demanded of a good.

Emery pharmaceutical uses an unstable chemical compound that must be kept in an environment where both temperature and humidity can be controlled. emery uses 825 pounds per month of the chemical, estimates the holding cost to be 50% of the purchase price (because of spoilage), and estimates order costs to be $48 per order. the cost schedules of two suppliers are as follows: vendor 1 vendor 2 quantity price/lb quantity price/lb 1-499 $17 1-399 $17.10 500-999 $16.75 400-799 $16.85 1000+ $16.50 800-1199 $16.60 1200+ $16.25 (a) what is the economic order quantity for each supplier? (b) what quantity should be ordered and which supplier should be used? (c) the total cost for the most economic order sire is $