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Finding the Fourth Proportional to 688.32, 1,033.92 and 640.80

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Solution

The fourth proportional to 688.32, 1,033.92 and 640.80 is: 962.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    688.32 : 1,033.92 = 640.80 : x
  2. Step 2: Convert to fraction form
    688.32/1,033.92 = 640.80/x
  3. Step 3: Cross multiply
    688.32x = 1,033.92 × 640.80
  4. Step 4: Simplify right side
    688.32x = 662,535.94
  5. Step 5: Solve for x
    x = 662,535.94/688.32
  6. Step 6: Final answer
    x = 962.54

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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.