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Finding the Fourth Proportional to 724.75, 1,000.12 and 405.70

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Solution

The fourth proportional to 724.75, 1,000.12 and 405.70 is: 559.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    724.75 : 1,000.12 = 405.70 : x
  2. Step 2: Convert to fraction form
    724.75/1,000.12 = 405.70/x
  3. Step 3: Cross multiply
    724.75x = 1,000.12 × 405.70
  4. Step 4: Simplify right side
    724.75x = 405,748.68
  5. Step 5: Solve for x
    x = 405,748.68/724.75
  6. Step 6: Final answer
    x = 559.85

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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.