Use numerical or graphical methods to find when the model

Question

Question: Tourism spending Global spending on travel and tourism (in billions of dollars) can be modeled by

f(x) = 252.576x^0.296

where x is the number of years after 1990 (Source: World Almanac).

(a) Does the graph of this function bend upward or bend downward?

(b) Graph this function.

(c) Use numerical or graphical methods to find when the model predicts that global spending will reach $613,000,000,000.