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Finding the Fourth Proportional to 135.80, 203.40 and 81.50

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Solution

The fourth proportional to 135.80, 203.40 and 81.50 is: 122.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.80 : 203.40 = 81.50 : x
  2. Step 2: Convert to fraction form
    135.80/203.40 = 81.50/x
  3. Step 3: Cross multiply
    135.80x = 203.40 × 81.50
  4. Step 4: Simplify right side
    135.80x = 16,577.10
  5. Step 5: Solve for x
    x = 16,577.10/135.80
  6. Step 6: Final answer
    x = 122.07

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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.