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Finding the Fourth Proportional to 280.38, 420.30 and 136.20

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Solution

The fourth proportional to 280.38, 420.30 and 136.20 is: 204.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.38 : 420.30 = 136.20 : x
  2. Step 2: Convert to fraction form
    280.38/420.30 = 136.20/x
  3. Step 3: Cross multiply
    280.38x = 420.30 × 136.20
  4. Step 4: Simplify right side
    280.38x = 57,244.86
  5. Step 5: Solve for x
    x = 57,244.86/280.38
  6. Step 6: Final answer
    x = 204.17

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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.