During an advertising campaign in a large city, the makers of Chip-O’s corn chips estimate that the number of people who have heard of Chip-O’s increases by a factor of 8 every 4 days.

1. If 100 people are given trial bags of Chip-O’s to start the campaign, write a function, $N(t)\text{,}$ for the number of people who have heard of Chip-O’s after $t$ days of advertising.
   $N(t)=$
2. Use your calculator to graph the function $N(t)$ on the domain $0 \le t \le 15\text{.}$
3. How many days should the makers run the campaign in order for Chip-O’s to be familiar to 51,200 people? Use algebraic methods to find your answer and verify on your graph.
   Answer: days