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Finding the Fourth Proportional to 81.60, 112.57 and 56.98

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Solution

The fourth proportional to 81.60, 112.57 and 56.98 is: 78.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.60 : 112.57 = 56.98 : x
  2. Step 2: Convert to fraction form
    81.60/112.57 = 56.98/x
  3. Step 3: Cross multiply
    81.60x = 112.57 × 56.98
  4. Step 4: Simplify right side
    81.60x = 6,414.24
  5. Step 5: Solve for x
    x = 6,414.24/81.60
  6. Step 6: Final answer
    x = 78.61

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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.