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Finding the Fourth Proportional to 61.92, 85.40 and 38.61

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Solution

The fourth proportional to 61.92, 85.40 and 38.61 is: 53.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.92 : 85.40 = 38.61 : x
  2. Step 2: Convert to fraction form
    61.92/85.40 = 38.61/x
  3. Step 3: Cross multiply
    61.92x = 85.40 × 38.61
  4. Step 4: Simplify right side
    61.92x = 3,297.25
  5. Step 5: Solve for x
    x = 3,297.25/61.92
  6. Step 6: Final answer
    x = 53.25

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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.