SOLUTION: Suppose the weights (W) of male student in MA102 are linearly related to their heights (h). If a student 150 cm tall weights 70kg, and a student 165 cm tall weights 110kg. a) write

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Question 909698: Suppose the weights (W) of male student in MA102 are linearly related to their heights (h). If a student 150 cm tall weights 70kg, and a student 165 cm tall weights 110kg. a) write an equation to express weight in terms of height. B) If there is a student with 90kg weight, how tall is this student?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
I will plot height (h) on the horizontal axis and
I will plot weight (W) on the vertical axis
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You are given 2 points:
( 150, 70 ) and
( 165, 110 )
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(a)
You can use the general point-slope formula:
+%28+W+-+70+%29+%2F+%28+h+-+150+%29+=+%28+110+-+70+%29+%2F+%28+165+-+150+%29+
+%28+W+-+70+%29+%2F+%28+h+-+150+%29+=+40+%2F+15+
+%28+W+-+70+%29+%2F+%28+h+-+150+%29+=+8+%2F+3+
Multiply both sides by +%28+h+-+150+%29%2A3+
+3%2A%28+W+-+70+%29+=+8%2A%28+h+-+150+%29+
+3W+-+210+=+8h+-+1200+
+3W+=+8h+-+990+
+W+=+%288%2F3%29%2Ah+-+330+
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check the answer:
+W+=+70+
+70+=+%288%2F3%29%2Ah+-+330+
+%288%2F3%29%2Ah+=+400+
+8h+=+1200+
+h+=+150+
OK
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(b)
+W+=+90+
+90+=+%288%2F3%29%2Ah+-+330+
+%288%2F3%29%2Ah+=+420+
+8h+=+1260+
+h+=+157.5+
The student weighs 157.5 kg