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Finding the Fourth Proportional to 688.49, 1,033.24 and 428.87

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Solution

The fourth proportional to 688.49, 1,033.24 and 428.87 is: 643.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.49 : 1,033.24 = 428.87 : x
  2. Step 2: Convert to fraction form
    688.49/1,033.24 = 428.87/x
  3. Step 3: Cross multiply
    688.49x = 1,033.24 × 428.87
  4. Step 4: Simplify right side
    688.49x = 443,120.47
  5. Step 5: Solve for x
    x = 443,120.47/688.49
  6. Step 6: Final answer
    x = 643.61

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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.