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A 7-foot tall stop sign creates a shadow that is 2 feet long. At the same time, a utility pole creates a shadow that is 11 feet long. How tall, in feet, is the utility pole?

off-topic
Guest Nov 21, 2018
 #1
avatar+128 
+1

Let's create a proportion:

actual height: shadow length

using what we have, we make the ratio

7ft: 2ft, and the ft cancels out to 7: 2

next up, we set up a variable x. the ratio of the utility pole is

x ft: 11ft, and the ft cancels out to x: 11, like before.

7:2 = 7/2

x:11 = x/11

they are equal, so 

7/2 = x/11

multiply both sides by 2:

7 = 2x/11

multiply both sides by 11:

77 = 2x

isolation x:

77/2 = x, and 77/2 is the answer

MATHEXPERTISE  Nov 21, 2018
 #2
avatar+656 
+1

The ratio is 7:2. If the pole's shadow is 11 feet long, we can multiply 11 by \(\dfrac{7}{2}\)  to get \(38\dfrac{1}{2}\). The pole is \(38.5\) feet tall. 

PartialMathematician  Nov 21, 2018
 #3
avatar+92787 
0

Thanks, ME and PM......!!!

 

cool cool cool

CPhill  Nov 21, 2018

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