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Finding the Fourth Proportional to 63.68, 87.87 and 39.12

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Solution

The fourth proportional to 63.68, 87.87 and 39.12 is: 53.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.68 : 87.87 = 39.12 : x
  2. Step 2: Convert to fraction form
    63.68/87.87 = 39.12/x
  3. Step 3: Cross multiply
    63.68x = 87.87 × 39.12
  4. Step 4: Simplify right side
    63.68x = 3,437.28
  5. Step 5: Solve for x
    x = 3,437.28/63.68
  6. Step 6: Final answer
    x = 53.98

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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.