The year y when sales were s million dollars for a particular electronics company can be modeled by the radical equation $y = 1.4 \sqrt { s - 2 } - 7$, where $y = 1$ represents 2010 , and so on. Use the model to predict the sales for 2015 to the nearest tenth of a million.
A) $89.2 million
B) $87.2 million
C) $90.2 million
D) $88.2 million

Question

Quizplus · Accepted Answer

To find the sales for 2015, set $y = 6$ (since 2015 is 5 years after 2010). Solve the equation $6 = 1.4 \sqrt{s - 2} - 7$ to find $s$. Solving gives $s \approx 88.2$ million.

The Year Y When Sales Were S Million Dollars for a Particular