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Finding the Fourth Proportional to 12.57, 18.87 and 8.78

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Solution

The fourth proportional to 12.57, 18.87 and 8.78 is: 13.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.57 : 18.87 = 8.78 : x
  2. Step 2: Convert to fraction form
    12.57/18.87 = 8.78/x
  3. Step 3: Cross multiply
    12.57x = 18.87 × 8.78
  4. Step 4: Simplify right side
    12.57x = 165.55
  5. Step 5: Solve for x
    x = 165.55/12.57
  6. Step 6: Final answer
    x = 13.17

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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.