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Finding the Fourth Proportional to 687.14, 947.81 and 477.21

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Solution

The fourth proportional to 687.14, 947.81 and 477.21 is: 658.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.14 : 947.81 = 477.21 : x
  2. Step 2: Convert to fraction form
    687.14/947.81 = 477.21/x
  3. Step 3: Cross multiply
    687.14x = 947.81 × 477.21
  4. Step 4: Simplify right side
    687.14x = 452,302.02
  5. Step 5: Solve for x
    x = 452,302.02/687.14
  6. Step 6: Final answer
    x = 658.24

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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.