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Finding the Fourth Proportional to 649.57, 897.21 and 639.85

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Solution

The fourth proportional to 649.57, 897.21 and 639.85 is: 883.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    649.57 : 897.21 = 639.85 : x
  2. Step 2: Convert to fraction form
    649.57/897.21 = 639.85/x
  3. Step 3: Cross multiply
    649.57x = 897.21 × 639.85
  4. Step 4: Simplify right side
    649.57x = 574,079.82
  5. Step 5: Solve for x
    x = 574,079.82/649.57
  6. Step 6: Final answer
    x = 883.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.