The manager at the local Ruby Tuesday's restaurant wanted to investigate the effect of music on the average revenue per customer. Each night for one month, fast- paced music was played. The following month, slow- paced music was played every night. The average revenue per customer for each month was compared. This method of gathering data is known as: a. surveys
b. experiments
c. focus groups
d. direct observation

Surface area = 80.4 cm²

Step-by-step explanation:

The diagram of both cylinders is attached below for a better understanding.

Surface area = 2πrh + 2πr²

236 = 2(3.14)(5)r + 2(3.14)r²

236 = 31.4r + 6.28r²

236 = 6.28(r² + 5r)

35.58 = r² + 5r

r = 3.97 cm

Two cylinders are in proportion if their heights and radius are in proportion:

Ratio of height of small cylinder to big cylinder = 3/5 = 0.6

So ratio of radius of both is also 0.6

Let R be the radius of small cylinder

ratio of radius of small cylinder to big cylinder = R / 3.97

R = (0.6)(3.97)

R = 2.38

R = 2.38cm and h = 3 cm

Surface area = 2πrh + 2πr²

Surface area = 2(3.14)(2.38)(3) + 2(3.14)(2.38)²

Surface area = 80.4115cm²

Round of to nearest tenth

Surface area = 80.4 cm²