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Finding the Fourth Proportional to 643.97, 963.88 and 424.78

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Solution

The fourth proportional to 643.97, 963.88 and 424.78 is: 635.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.97 : 963.88 = 424.78 : x
  2. Step 2: Convert to fraction form
    643.97/963.88 = 424.78/x
  3. Step 3: Cross multiply
    643.97x = 963.88 × 424.78
  4. Step 4: Simplify right side
    643.97x = 409,436.95
  5. Step 5: Solve for x
    x = 409,436.95/643.97
  6. Step 6: Final answer
    x = 635.80

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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.