Question

An average of 1.8% of Apex Alarm systems need a battery replacement after 3 years in operation. Seventy-two battery replacements are needed in the next three years. What is the best estimate of how many Apex Alarm systems were sold?

Answer 1

.018x = 72
solve for x

Answer 2

I got 4000 is that right?

Answer 3

yes

check it by taking 1.8% of it