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Finding the Fourth Proportional to 871.87, 1,203.20 and 478.90

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Solution

The fourth proportional to 871.87, 1,203.20 and 478.90 is: 660.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.87 : 1,203.20 = 478.90 : x
  2. Step 2: Convert to fraction form
    871.87/1,203.20 = 478.90/x
  3. Step 3: Cross multiply
    871.87x = 1,203.20 × 478.90
  4. Step 4: Simplify right side
    871.87x = 576,206.46
  5. Step 5: Solve for x
    x = 576,206.46/871.87
  6. Step 6: Final answer
    x = 660.89

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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.