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Finding the Fourth Proportional to 871.39, 1,306.15 and 408.77

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Solution

The fourth proportional to 871.39, 1,306.15 and 408.77 is: 612.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    871.39 : 1,306.15 = 408.77 : x
  2. Step 2: Convert to fraction form
    871.39/1,306.15 = 408.77/x
  3. Step 3: Cross multiply
    871.39x = 1,306.15 × 408.77
  4. Step 4: Simplify right side
    871.39x = 533,914.94
  5. Step 5: Solve for x
    x = 533,914.94/871.39
  6. Step 6: Final answer
    x = 612.72

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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.