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Finding the Fourth Proportional to 13.96, 20.86 and 12.80

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Solution

The fourth proportional to 13.96, 20.86 and 12.80 is: 19.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    13.96 : 20.86 = 12.80 : x
  2. Step 2: Convert to fraction form
    13.96/20.86 = 12.80/x
  3. Step 3: Cross multiply
    13.96x = 20.86 × 12.80
  4. Step 4: Simplify right side
    13.96x = 267.01
  5. Step 5: Solve for x
    x = 267.01/13.96
  6. Step 6: Final answer
    x = 19.13

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.