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Finding the Fourth Proportional to 63.57, 87.70 and 42.85

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Solution

The fourth proportional to 63.57, 87.70 and 42.85 is: 59.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.57 : 87.70 = 42.85 : x
  2. Step 2: Convert to fraction form
    63.57/87.70 = 42.85/x
  3. Step 3: Cross multiply
    63.57x = 87.70 × 42.85
  4. Step 4: Simplify right side
    63.57x = 3,757.95
  5. Step 5: Solve for x
    x = 3,757.95/63.57
  6. Step 6: Final answer
    x = 59.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.