I would say that the median is the best measure for the center as there are two major outliers (16 and 18)
When naming triangles we name them by the letters on each corner so only answers with T, A, and X in them are correct, so TAX, XTA, and AXT
Given:
pool length : 10 yards
pool width : 8 yards
Area = 10 yds * 8 yds = 80 yd²
(10 + 2x)(8 + 2x) = 120
10(8 + 2x) + 2x(8+2x) = 120
80 + 20x + 16x + 4x² = 120
4x² + 36x + 80 - 120 = 0
4x² + 36x - 40 = 0
4(x² + 9x - 10) = 0
4(x + 10)(x - 1) = 0
x + 10 = 0
x = -10
x - 1 = 0
x = 1
the width of the deck is 1 yard