Hello, Maziana!

We estimate the rate at which the total personal income is rising in a city.

In 1999, the population of the city was 939,200, and increasing at 9500 per year.

The average annual income was $30,388 per capita, and increasing at $1300 per year.

Use the Product Rule and these figures to estimate the rate

at which total personal income was rising in the area in 1999.

Let = number of years since 1999.

After years, the population is: .

After years, the average income is: . dollars.

Hence, after years, the total income is: .

They are asking for

Differentiate using the Product Rule.

. . and simplify.