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Finding the Fourth Proportional to 81.66, 112.59 and 70.86

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Solution

The fourth proportional to 81.66, 112.59 and 70.86 is: 97.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.66 : 112.59 = 70.86 : x
  2. Step 2: Convert to fraction form
    81.66/112.59 = 70.86/x
  3. Step 3: Cross multiply
    81.66x = 112.59 × 70.86
  4. Step 4: Simplify right side
    81.66x = 7,978.13
  5. Step 5: Solve for x
    x = 7,978.13/81.66
  6. Step 6: Final answer
    x = 97.70

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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.