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Finding the Fourth Proportional to 871.11, 1,307.28 and 408.91

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Solution

The fourth proportional to 871.11, 1,307.28 and 408.91 is: 613.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.11 : 1,307.28 = 408.91 : x
  2. Step 2: Convert to fraction form
    871.11/1,307.28 = 408.91/x
  3. Step 3: Cross multiply
    871.11x = 1,307.28 × 408.91
  4. Step 4: Simplify right side
    871.11x = 534,553.92
  5. Step 5: Solve for x
    x = 534,553.92/871.11
  6. Step 6: Final answer
    x = 613.65

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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.