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Finding the Fourth Proportional to 81.87, 122.80 and 47.64

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Solution

The fourth proportional to 81.87, 122.80 and 47.64 is: 71.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.87 : 122.80 = 47.64 : x
  2. Step 2: Convert to fraction form
    81.87/122.80 = 47.64/x
  3. Step 3: Cross multiply
    81.87x = 122.80 × 47.64
  4. Step 4: Simplify right side
    81.87x = 5,850.19
  5. Step 5: Solve for x
    x = 5,850.19/81.87
  6. Step 6: Final answer
    x = 71.46

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.