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Finding the Fourth Proportional to 425.79, 638.68 and 133.28

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Solution

The fourth proportional to 425.79, 638.68 and 133.28 is: 199.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    425.79 : 638.68 = 133.28 : x
  2. Step 2: Convert to fraction form
    425.79/638.68 = 133.28/x
  3. Step 3: Cross multiply
    425.79x = 638.68 × 133.28
  4. Step 4: Simplify right side
    425.79x = 85,123.27
  5. Step 5: Solve for x
    x = 85,123.27/425.79
  6. Step 6: Final answer
    x = 199.92

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.