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Finding the Fourth Proportional to 872.82, 1,309.40 and 287.85

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Solution

The fourth proportional to 872.82, 1,309.40 and 287.85 is: 431.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.82 : 1,309.40 = 287.85 : x
  2. Step 2: Convert to fraction form
    872.82/1,309.40 = 287.85/x
  3. Step 3: Cross multiply
    872.82x = 1,309.40 × 287.85
  4. Step 4: Simplify right side
    872.82x = 376,909.35
  5. Step 5: Solve for x
    x = 376,909.35/872.82
  6. Step 6: Final answer
    x = 431.83

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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.