Question

The table shows the number of cell phone towers a company will build as the number of its customers increases. Complete a and b below.
Cell Phone Towers
Customers​ (thousands)
Towers
3.25
143
4.25
187
5.25
231
7.25
319
Question content area bottom
Part 1
a. Is the relationship between number of towers and number of customers​ proportional? Explain. Choose the correct answer below​ and, if​ necessary, fill in the answer box to complete your choice.
A.
Yes. The ratios of towers to customers​ (thousands) are all equivalent to a unit rate of
  
StartFraction 44 Over 1 EndFraction
.
Your answer is correct.B.
No. The ratios of towers to customers are not all equivalent.
Part 2
b. If there are 484 ​towers, how many customers does the company​ have? Write a proportion you can use to solve. Choose the correct proportion.

Answer 1

Part a.
Yes. Each ratio towers : customers (in thousands) is constant: 143/3.25 = 187/4.25 = 231/5.25 = 319/7.25 = 44. So the unit rate is 44 towers per 1 thousand customers.

Part b.
Use the proportion 44/1 = 484/x (x in thousands of customers). Solve: x = 484/44 = 11, so 11 thousand customers = 11,000 customers.