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Finding the Fourth Proportional to 643.40, 963.03 and 458.20

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Solution

The fourth proportional to 643.40, 963.03 and 458.20 is: 685.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.40 : 963.03 = 458.20 : x
  2. Step 2: Convert to fraction form
    643.40/963.03 = 458.20/x
  3. Step 3: Cross multiply
    643.40x = 963.03 × 458.20
  4. Step 4: Simplify right side
    643.40x = 441,260.35
  5. Step 5: Solve for x
    x = 441,260.35/643.40
  6. Step 6: Final answer
    x = 685.83

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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.