The numbers of polio cases in the world are shown in the table for various years.

Year	Number of Polio Cases (thousands)
1988	350
1992	138
1996	36
2000	4
1	3.2
2007	1.3

Let $\displaystyle {f{{\left({t}\right)}}}$ be the number of polio cases in the world t years since 1980.

Use a graphing calculator to draw a scattergram of the data. Is it better to model the data by using a linear or exponential model? Select an answer Exponential Linear

Find an equation of f. Hint

$\displaystyle {f{{\left({t}\right)}}}=$Preview Question 6 Part 2 of 7   Round the coefficients to 2 digits.

The number of polio cases Select an answer decreasing increasing by Select an answer 100% 0% 24.05% 2405% per year.

Predict the number of polio cases in 2018.

Hint

Predict in which year there will be 1 case of polio.



Find the approximate half-life of the number of polio cases. Hint

years