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Finding the Fourth Proportional to 478.13, 717.39 and 285.75

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Solution

The fourth proportional to 478.13, 717.39 and 285.75 is: 428.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    478.13 : 717.39 = 285.75 : x
  2. Step 2: Convert to fraction form
    478.13/717.39 = 285.75/x
  3. Step 3: Cross multiply
    478.13x = 717.39 × 285.75
  4. Step 4: Simplify right side
    478.13x = 204,994.19
  5. Step 5: Solve for x
    x = 204,994.19/478.13
  6. Step 6: Final answer
    x = 428.75

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.