Answer:
z = 1.25
Step-by-step explanation:
The inequality should be

The sign on the right is only a 'smaller than' sign because he spent less than 180.
On the left, assuming that even if Calvin took nobody (poor Calvin), we should assume that he at least went himself, hence he spent a minimum of $12.
Not to sure about this one. Maybe try google.
The answer would be 2345.6