A certain species of animal is endangered and its population is decreasing at an annual rate of \( 30 \% \) . There are currently \( 190 \) animals in the population. Which is the exponential equation that represents the population over time?
A linear function that models data is described below. Find the slope of the model. Then describe what this means in terms of the rate of change of the dependent variable per unit change in the independent variable. The linear function \( f ( x ) = - 0.41 x + 28.6 \) models the percentage of adults in a country who smoked cigarettes, \( f ( x ) \) , \( x \) years after \( 1997 \) .
The slope is \( \square \) . (Type an integer or a decimal.)