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Finding the Fourth Proportional to 280.90, 421.31 and 136.58

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Solution

The fourth proportional to 280.90, 421.31 and 136.58 is: 204.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.90 : 421.31 = 136.58 : x
  2. Step 2: Convert to fraction form
    280.90/421.31 = 136.58/x
  3. Step 3: Cross multiply
    280.90x = 421.31 × 136.58
  4. Step 4: Simplify right side
    280.90x = 57,542.52
  5. Step 5: Solve for x
    x = 57,542.52/280.90
  6. Step 6: Final answer
    x = 204.85

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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.