Answer
$\approx -\$16.67$ per month
The average price of a new laptop computer decreases by $\$16.67$ per month.
Work Step by Step
In Dec 2006, the average price of a new laptop computer was $\$1,200$.
In Dec 2007, the average price of a new laptop computer was $\$1,000$.
To find the rate of change in the average price of a new laptop computer, divide the change in average price by the time.
From Dec 2006 to Dec 2007, there are 12 months.
Thus, the average rate of change in the average price of a brand new laptop computer is:
$=\dfrac{\$1000-\$1200}{12 \text{ months}}=\dfrac{-\$200}{12\text{ months}}\approx -\$16.67$ per month