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Finding the Fourth Proportional to 338.78, 508.17 and 133.21

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Solution

The fourth proportional to 338.78, 508.17 and 133.21 is: 199.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    338.78 : 508.17 = 133.21 : x
  2. Step 2: Convert to fraction form
    338.78/508.17 = 133.21/x
  3. Step 3: Cross multiply
    338.78x = 508.17 × 133.21
  4. Step 4: Simplify right side
    338.78x = 67,693.33
  5. Step 5: Solve for x
    x = 67,693.33/338.78
  6. Step 6: Final answer
    x = 199.82

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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.