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Finding the Fourth Proportional to 13.19, 19.74 and 12.55

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Solution

The fourth proportional to 13.19, 19.74 and 12.55 is: 18.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.19 : 19.74 = 12.55 : x
  2. Step 2: Convert to fraction form
    13.19/19.74 = 12.55/x
  3. Step 3: Cross multiply
    13.19x = 19.74 × 12.55
  4. Step 4: Simplify right side
    13.19x = 247.74
  5. Step 5: Solve for x
    x = 247.74/13.19
  6. Step 6: Final answer
    x = 18.78

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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.