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?
I got 4000 is that right?
.018x = 72
solve for x
yes
check it by taking 1.8% of it
To estimate the number of Apex Alarm systems sold, we can use the information given. We know that an average of 1.8% of these systems need a battery replacement after 3 years.
Let's calculate the number of systems that correspond to 1.8% by setting up a proportion:
1.8% = 72 / X
Now, cross-multiply to solve for X:
(1.8 / 100) * X = 72
Dividing both sides by 1.8 / 100 will give us the estimate of X:
X = (72 * 100) / 1.8
Evaluating this equation gives us:
X ≈ 4000
Therefore, the best estimate is that approximately 4000 Apex Alarm systems were sold.