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Finding the Fourth Proportional to 404.20, 557.51 and 256.78

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Solution

The fourth proportional to 404.20, 557.51 and 256.78 is: 354.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    404.20 : 557.51 = 256.78 : x
  2. Step 2: Convert to fraction form
    404.20/557.51 = 256.78/x
  3. Step 3: Cross multiply
    404.20x = 557.51 × 256.78
  4. Step 4: Simplify right side
    404.20x = 143,157.42
  5. Step 5: Solve for x
    x = 143,157.42/404.20
  6. Step 6: Final answer
    x = 354.17

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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.