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Finding the Fourth Proportional to 14.28, 21.39 and 12.39

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Solution

The fourth proportional to 14.28, 21.39 and 12.39 is: 18.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    14.28 : 21.39 = 12.39 : x
  2. Step 2: Convert to fraction form
    14.28/21.39 = 12.39/x
  3. Step 3: Cross multiply
    14.28x = 21.39 × 12.39
  4. Step 4: Simplify right side
    14.28x = 265.02
  5. Step 5: Solve for x
    x = 265.02/14.28
  6. Step 6: Final answer
    x = 18.56

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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.