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Finding the Fourth Proportional to 218.39, 327.61 and 81.45

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Solution

The fourth proportional to 218.39, 327.61 and 81.45 is: 122.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.39 : 327.61 = 81.45 : x
  2. Step 2: Convert to fraction form
    218.39/327.61 = 81.45/x
  3. Step 3: Cross multiply
    218.39x = 327.61 × 81.45
  4. Step 4: Simplify right side
    218.39x = 26,683.94
  5. Step 5: Solve for x
    x = 26,683.94/218.39
  6. Step 6: Final answer
    x = 122.19

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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.