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Finding the Fourth Proportional to 638.71, 881.38 and 358.91

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Solution

The fourth proportional to 638.71, 881.38 and 358.91 is: 495.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.71 : 881.38 = 358.91 : x
  2. Step 2: Convert to fraction form
    638.71/881.38 = 358.91/x
  3. Step 3: Cross multiply
    638.71x = 881.38 × 358.91
  4. Step 4: Simplify right side
    638.71x = 316,336.10
  5. Step 5: Solve for x
    x = 316,336.10/638.71
  6. Step 6: Final answer
    x = 495.27

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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.