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Finding the Fourth Proportional to 135.41, 202.88 and 81.20

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Solution

The fourth proportional to 135.41, 202.88 and 81.20 is: 121.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    135.41 : 202.88 = 81.20 : x
  2. Step 2: Convert to fraction form
    135.41/202.88 = 81.20/x
  3. Step 3: Cross multiply
    135.41x = 202.88 × 81.20
  4. Step 4: Simplify right side
    135.41x = 16,473.45
  5. Step 5: Solve for x
    x = 16,473.45/135.41
  6. Step 6: Final answer
    x = 121.66

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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.