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Finding the Fourth Proportional to 135.87, 203.49 and 78

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Solution

The fourth proportional to 135.87, 203.49 and 78 is: 116.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.87 : 203.49 = 78 : x
  2. Step 2: Convert to fraction form
    135.87/203.49 = 78/x
  3. Step 3: Cross multiply
    135.87x = 203.49 × 78
  4. Step 4: Simplify right side
    135.87x = 15,872.22
  5. Step 5: Solve for x
    x = 15,872.22/135.87
  6. Step 6: Final answer
    x = 116.82

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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.