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Finding the Fourth Proportional to 14.20, 21.40 and 12.48

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Solution

The fourth proportional to 14.20, 21.40 and 12.48 is: 18.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    14.20 : 21.40 = 12.48 : x
  2. Step 2: Convert to fraction form
    14.20/21.40 = 12.48/x
  3. Step 3: Cross multiply
    14.20x = 21.40 × 12.48
  4. Step 4: Simplify right side
    14.20x = 267.07
  5. Step 5: Solve for x
    x = 267.07/14.20
  6. Step 6: Final answer
    x = 18.81

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.