Add 145, 156, 210. and 255 then divide by 4. The mean equals 184.
Shiela is 0.61 meters taller than her son.
The answer is 10 cm
Imagine cement cover as a rectangle which volume is 660,000,000 cm3. So this rectangle has width (w = 60m), length (l = 110m), and height (h = ?). The height of the rectangle is actually a thickness of the cement layer. So, we will use the formula for the volume (V) of the rectangle to calculate the thickness:
V = w · l · h
It is given:
V = 660,000,000 cm³
w = 60 m = 60 · 100 cm = 6,000 cm
l = 110 m = 110 · 100 cm = 11,000 cm
h = ?
Using the formula: V = w · l · h
660,000,000 = 6,000 · 11,000 · h
660,000,000 = 66,000,000 · h
⇒ h = 660,000,000 ÷ 66,000,000 = 10 cm
Using the the density(D)-mass(m)-volume(V) formula

, we can calculate the volume