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Finding the Fourth Proportional to 872.87, 1,309.50 and 287.87

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Solution

The fourth proportional to 872.87, 1,309.50 and 287.87 is: 431.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    872.87 : 1,309.50 = 287.87 : x
  2. Step 2: Convert to fraction form
    872.87/1,309.50 = 287.87/x
  3. Step 3: Cross multiply
    872.87x = 1,309.50 × 287.87
  4. Step 4: Simplify right side
    872.87x = 376,959.22
  5. Step 5: Solve for x
    x = 376,959.22/872.87
  6. Step 6: Final answer
    x = 431.86

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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.