Question

For homework, Anya had to find the width of a bedroom after the scale changed from 1 inch : 4 feet to 1 inch : 7 feet. Her work is shown below.

1 inch = 4 feet. 1 inches = 7 feet. A rectangle with length of 4 inches and width of 2 inches. StartFraction 1 over 7 EndFraction = StartFraction x over 2 EndFraction. 7 x = 2. x = StartFraction 2 over 7 EndFraction feet.

1
7
= x
2
7x = 2x = 2
7
feet

What error did Anya make?

Answer 1

its A

Explanation:

Answer 2

she set up the proportion incorrectly; the second ratio should be 2/x

Explanation:

To obtain the width :

Scale drawing :

Initial = 1 inch = 4 feet

New = 1 inch = 7 feet

Width of rectangle = 2 inches

New width should be in the form :

new scale = width of rectangle / width of drawing

If width of drawing = x

1 / 7 = 2 / x

Cross multiply

x = 7*2

x = 14