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Finding the Fourth Proportional to 81.58, 122.38 and 70.64

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Solution

The fourth proportional to 81.58, 122.38 and 70.64 is: 105.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.58 : 122.38 = 70.64 : x
  2. Step 2: Convert to fraction form
    81.58/122.38 = 70.64/x
  3. Step 3: Cross multiply
    81.58x = 122.38 × 70.64
  4. Step 4: Simplify right side
    81.58x = 8,644.92
  5. Step 5: Solve for x
    x = 8,644.92/81.58
  6. Step 6: Final answer
    x = 105.97

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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.