In the first quarter of 2009, worldwide demand for smart phones was 174 million at an

average wholesale price of $162 per phone. A year later the price had dropped to $152

and the demand increased to 213 million phones.

(A) Find a linear demand function q = mp + b for this data, where q is the demand for smart phones, in millions, and p is the price in dollars. Show work/explain reasoning in determining the values m and b for your function. Fill in the summary table at the bottom of this page when you are finished.

(B) Use your function to find the demand if the average wholesale price is $158. Show work and put final answer in sentence form.

(C) What will be the price when the demand has dropped to 140 million phones? Show work and put final answer in sentence form.

(D) Interpret the slope of your demand function. Your interpretation should be in the form of a sentence like: "For every ____ increase in price, sales of smart phones decreased by ________ units."