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Finding the Fourth Proportional to 42.31, 63.43 and 13.40

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Solution

The fourth proportional to 42.31, 63.43 and 13.40 is: 20.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.31 : 63.43 = 13.40 : x
  2. Step 2: Convert to fraction form
    42.31/63.43 = 13.40/x
  3. Step 3: Cross multiply
    42.31x = 63.43 × 13.40
  4. Step 4: Simplify right side
    42.31x = 849.90
  5. Step 5: Solve for x
    x = 849.90/42.31
  6. Step 6: Final answer
    x = 20.09

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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.