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Finding the Fourth Proportional to 280.15, 420.17 and 133.85

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Solution

The fourth proportional to 280.15, 420.17 and 133.85 is: 200.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.15 : 420.17 = 133.85 : x
  2. Step 2: Convert to fraction form
    280.15/420.17 = 133.85/x
  3. Step 3: Cross multiply
    280.15x = 420.17 × 133.85
  4. Step 4: Simplify right side
    280.15x = 56,239.75
  5. Step 5: Solve for x
    x = 56,239.75/280.15
  6. Step 6: Final answer
    x = 200.75

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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.