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Finding the Fourth Proportional to 135.50, 203.18 and 81.50

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Solution

The fourth proportional to 135.50, 203.18 and 81.50 is: 122.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.50 : 203.18 = 81.50 : x
  2. Step 2: Convert to fraction form
    135.50/203.18 = 81.50/x
  3. Step 3: Cross multiply
    135.50x = 203.18 × 81.50
  4. Step 4: Simplify right side
    135.50x = 16,559.17
  5. Step 5: Solve for x
    x = 16,559.17/135.50
  6. Step 6: Final answer
    x = 122.21

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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.