Final answer:
The cost per person can be expressed as a function of the number of people on the tour. Audrianna would make $13 for a tour with 19 people.
Step-by-step explanation:
The cost per person c can be expressed as a function of the number of people n on the tour as follows:
If Audrianna is giving a tour to one person, the cost would be $49.
If there are additional people on the tour, the price per person would be $2 less than the previous person. So, if there are 2 people on the tour, the cost would be $49 - $2 = $47 per person.
Using this pattern, we can write the function as:
c(n) = 49 - 2(n - 1)
To find out how much Audrianna makes for a tour with 19 people, we plug in 19 for n in the function:
c(19) = 49 - 2(19 - 1) = 49 - 2(18) = 49 - 36 = $13