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Finding the Fourth Proportional to 81.31, 122 and 49.25

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Solution

The fourth proportional to 81.31, 122 and 49.25 is: 73.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.31 : 122 = 49.25 : x
  2. Step 2: Convert to fraction form
    81.31/122 = 49.25/x
  3. Step 3: Cross multiply
    81.31x = 122 × 49.25
  4. Step 4: Simplify right side
    81.31x = 6,008.50
  5. Step 5: Solve for x
    x = 6,008.50/81.31
  6. Step 6: Final answer
    x = 73.90

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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.