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Finding the Fourth Proportional to 218.55, 327.60 and 81.51

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Solution

The fourth proportional to 218.55, 327.60 and 81.51 is: 122.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.55 : 327.60 = 81.51 : x
  2. Step 2: Convert to fraction form
    218.55/327.60 = 81.51/x
  3. Step 3: Cross multiply
    218.55x = 327.60 × 81.51
  4. Step 4: Simplify right side
    218.55x = 26,702.68
  5. Step 5: Solve for x
    x = 26,702.68/218.55
  6. Step 6: Final answer
    x = 122.18

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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.