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Finding the Fourth Proportional to 218.21, 327.29 and 81.25

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Solution

The fourth proportional to 218.21, 327.29 and 81.25 is: 121.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.21 : 327.29 = 81.25 : x
  2. Step 2: Convert to fraction form
    218.21/327.29 = 81.25/x
  3. Step 3: Cross multiply
    218.21x = 327.29 × 81.25
  4. Step 4: Simplify right side
    218.21x = 26,590.68
  5. Step 5: Solve for x
    x = 26,590.68/218.21
  6. Step 6: Final answer
    x = 121.86

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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.