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Finding the Fourth Proportional to 218.72, 327.79 and 81.63

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Solution

The fourth proportional to 218.72, 327.79 and 81.63 is: 122.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.72 : 327.79 = 81.63 : x
  2. Step 2: Convert to fraction form
    218.72/327.79 = 81.63/x
  3. Step 3: Cross multiply
    218.72x = 327.79 × 81.63
  4. Step 4: Simplify right side
    218.72x = 26,757.50
  5. Step 5: Solve for x
    x = 26,757.50/218.72
  6. Step 6: Final answer
    x = 122.34

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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.