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Finding the Fourth Proportional to 404.78, 557.61 and 390.38

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Solution

The fourth proportional to 404.78, 557.61 and 390.38 is: 537.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    404.78 : 557.61 = 390.38 : x
  2. Step 2: Convert to fraction form
    404.78/557.61 = 390.38/x
  3. Step 3: Cross multiply
    404.78x = 557.61 × 390.38
  4. Step 4: Simplify right side
    404.78x = 217,679.79
  5. Step 5: Solve for x
    x = 217,679.79/404.78
  6. Step 6: Final answer
    x = 537.77

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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.