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Finding the Fourth Proportional to 638.56, 881.19 and 358.78

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Solution

The fourth proportional to 638.56, 881.19 and 358.78 is: 495.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.56 : 881.19 = 358.78 : x
  2. Step 2: Convert to fraction form
    638.56/881.19 = 358.78/x
  3. Step 3: Cross multiply
    638.56x = 881.19 × 358.78
  4. Step 4: Simplify right side
    638.56x = 316,154.21
  5. Step 5: Solve for x
    x = 316,154.21/638.56
  6. Step 6: Final answer
    x = 495.11

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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.