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Finding the Fourth Proportional to 75.31, 103.92 and 42.12

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Solution

The fourth proportional to 75.31, 103.92 and 42.12 is: 58.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.31 : 103.92 = 42.12 : x
  2. Step 2: Convert to fraction form
    75.31/103.92 = 42.12/x
  3. Step 3: Cross multiply
    75.31x = 103.92 × 42.12
  4. Step 4: Simplify right side
    75.31x = 4,376.59
  5. Step 5: Solve for x
    x = 4,376.59/75.31
  6. Step 6: Final answer
    x = 58.12

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.