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Finding the Fourth Proportional to 218.77, 328.28 and 81.83

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Solution

The fourth proportional to 218.77, 328.28 and 81.83 is: 122.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.77 : 328.28 = 81.83 : x
  2. Step 2: Convert to fraction form
    218.77/328.28 = 81.83/x
  3. Step 3: Cross multiply
    218.77x = 328.28 × 81.83
  4. Step 4: Simplify right side
    218.77x = 26,861.51
  5. Step 5: Solve for x
    x = 26,861.51/218.77
  6. Step 6: Final answer
    x = 122.78

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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.