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Finding the Fourth Proportional to 638.71, 881.20 and 358.90

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Solution

The fourth proportional to 638.71, 881.20 and 358.90 is: 495.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.71 : 881.20 = 358.90 : x
  2. Step 2: Convert to fraction form
    638.71/881.20 = 358.90/x
  3. Step 3: Cross multiply
    638.71x = 881.20 × 358.90
  4. Step 4: Simplify right side
    638.71x = 316,262.68
  5. Step 5: Solve for x
    x = 316,262.68/638.71
  6. Step 6: Final answer
    x = 495.16

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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.