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Finding the Fourth Proportional to 280.38, 420.28 and 135.92

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Solution

The fourth proportional to 280.38, 420.28 and 135.92 is: 203.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.38 : 420.28 = 135.92 : x
  2. Step 2: Convert to fraction form
    280.38/420.28 = 135.92/x
  3. Step 3: Cross multiply
    280.38x = 420.28 × 135.92
  4. Step 4: Simplify right side
    280.38x = 57,124.46
  5. Step 5: Solve for x
    x = 57,124.46/280.38
  6. Step 6: Final answer
    x = 203.74

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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.