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Finding the Fourth Proportional to 403.89, 606.85 and 257.70

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Solution

The fourth proportional to 403.89, 606.85 and 257.70 is: 387.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    403.89 : 606.85 = 257.70 : x
  2. Step 2: Convert to fraction form
    403.89/606.85 = 257.70/x
  3. Step 3: Cross multiply
    403.89x = 606.85 × 257.70
  4. Step 4: Simplify right side
    403.89x = 156,385.25
  5. Step 5: Solve for x
    x = 156,385.25/403.89
  6. Step 6: Final answer
    x = 387.20

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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.