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Finding the Fourth Proportional to 812.28, 1,120.86 and 480.72

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Solution

The fourth proportional to 812.28, 1,120.86 and 480.72 is: 663.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.28 : 1,120.86 = 480.72 : x
  2. Step 2: Convert to fraction form
    812.28/1,120.86 = 480.72/x
  3. Step 3: Cross multiply
    812.28x = 1,120.86 × 480.72
  4. Step 4: Simplify right side
    812.28x = 538,819.82
  5. Step 5: Solve for x
    x = 538,819.82/812.28
  6. Step 6: Final answer
    x = 663.34

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Half scale
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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.