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Finding the Fourth Proportional to 814.11, 1,220.81 and 258.66

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Solution

The fourth proportional to 814.11, 1,220.81 and 258.66 is: 387.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    814.11 : 1,220.81 = 258.66 : x
  2. Step 2: Convert to fraction form
    814.11/1,220.81 = 258.66/x
  3. Step 3: Cross multiply
    814.11x = 1,220.81 × 258.66
  4. Step 4: Simplify right side
    814.11x = 315,773.42
  5. Step 5: Solve for x
    x = 315,773.42/814.11
  6. Step 6: Final answer
    x = 387.88

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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.