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Finding the Fourth Proportional to 63.45, 87.55 and 38.90

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Solution

The fourth proportional to 63.45, 87.55 and 38.90 is: 53.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    63.45 : 87.55 = 38.90 : x
  2. Step 2: Convert to fraction form
    63.45/87.55 = 38.90/x
  3. Step 3: Cross multiply
    63.45x = 87.55 × 38.90
  4. Step 4: Simplify right side
    63.45x = 3,405.82
  5. Step 5: Solve for x
    x = 3,405.82/63.45
  6. Step 6: Final answer
    x = 53.68

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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.