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Finding the Fourth Proportional to 280.11, 420.20 and 135.82

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Solution

The fourth proportional to 280.11, 420.20 and 135.82 is: 203.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    280.11 : 420.20 = 135.82 : x
  2. Step 2: Convert to fraction form
    280.11/420.20 = 135.82/x
  3. Step 3: Cross multiply
    280.11x = 420.20 × 135.82
  4. Step 4: Simplify right side
    280.11x = 57,071.56
  5. Step 5: Solve for x
    x = 57,071.56/280.11
  6. Step 6: Final answer
    x = 203.75

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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.