Answer:
Average customer life value
CLV = 1260
Step-by-step explanation:

Fis, we will calcualteteh gross margin.
For that we need the revenue:
We will calculate the average revenue per year:
50% 30 dollars per month = 180
40% 50 dollars per month = 240
10% 80 dollars per month = 96
average annual revenue per customer: 516
now we ill calcualte the gross margin:
revenue 516
maintenance (45)
administrative (30)
gross margin 441

CLV = 1260