Solution:
Matte Satin Glossy Total
Homeowners 0.08 0.20 0.24 0.52
Contractors 0.04 0.26 0.18 0.48
Total 0.12 0.46 0.42 1
Approximately what percentage of contractors prefer the glossy finish?
Answer: Percentage of contractors who prefer the glossy finish is:
or 
Therefore, the option D. 37.5% is correct
The length of the altitude is 9.5 cm.
The altitude bisects the base of the equilateral triangle (this is because the two sides emerging from the vertex are equal). This gives us a right triangle with leg 5.5 and hypotenuse 11. We use the Pythagorean theorem:
5.5² + h² = 11²
30.25 + h² = 121
Subtract 30.25 from both sides:
30.25 + h² - 30.25 = 121 - 30.25
h² = 90.75
Take the square root of both sides:
√h² = √90.75
h = 9.5