Question

An architect built a scale model of a shopping mall. On the model, a circular fountain is 21 inches tall and 17.5 inches in diameter. If the actual fountain is to be 6 feet tall, what will its diameter be?

Answer 1

Answer:

The diameter is 5ft

Step-by-step explanation:

Given

$Height : Diameter = 21\ in: 17.5\ in$

Required

Determine the diameter when the height is 6ft

Recall that the scale is a ratio of height to diameter;

So 6ft height can be represented on the following scale model;

$Height : Diameter = 6ft : x$

Convert to fraction

$\frac{Height}{Diameter} = \frac{6}{x}$ ---- (1)

Recall that:

$Height : Diameter = 21\ in: 17.5\ in$

Convert to fraction

$\frac{Height}{Diameter} = \frac{21 }{17.5}$ ---- (2)

Equate (1) & (2)

$\frac{6}{x}= \frac{21 }{17.5}$

Cross Multiply

$21 * x = 6 * 17.5$

$21x = 105$

$x = 105/21$

$x = 5$

Hence, the diameter is 5ft