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Finding the Fourth Proportional to 135.80, 203.40 and 87.20

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Solution

The fourth proportional to 135.80, 203.40 and 87.20 is: 130.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.80 : 203.40 = 87.20 : x
  2. Step 2: Convert to fraction form
    135.80/203.40 = 87.20/x
  3. Step 3: Cross multiply
    135.80x = 203.40 × 87.20
  4. Step 4: Simplify right side
    135.80x = 17,736.48
  5. Step 5: Solve for x
    x = 17,736.48/135.80
  6. Step 6: Final answer
    x = 130.61

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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.