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Finding the Fourth Proportional to 81.50, 122.13 and 58.71

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Solution

The fourth proportional to 81.50, 122.13 and 58.71 is: 87.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.50 : 122.13 = 58.71 : x
  2. Step 2: Convert to fraction form
    81.50/122.13 = 58.71/x
  3. Step 3: Cross multiply
    81.50x = 122.13 × 58.71
  4. Step 4: Simplify right side
    81.50x = 7,170.25
  5. Step 5: Solve for x
    x = 7,170.25/81.50
  6. Step 6: Final answer
    x = 87.98

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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.