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Finding the Fourth Proportional to 12.79, 19.20 and 12.55

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Solution

The fourth proportional to 12.79, 19.20 and 12.55 is: 18.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.79 : 19.20 = 12.55 : x
  2. Step 2: Convert to fraction form
    12.79/19.20 = 12.55/x
  3. Step 3: Cross multiply
    12.79x = 19.20 × 12.55
  4. Step 4: Simplify right side
    12.79x = 240.96
  5. Step 5: Solve for x
    x = 240.96/12.79
  6. Step 6: Final answer
    x = 18.84

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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.