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Finding the Fourth Proportional to 643.57, 964.37 and 426.69

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Solution

The fourth proportional to 643.57, 964.37 and 426.69 is: 639.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.57 : 964.37 = 426.69 : x
  2. Step 2: Convert to fraction form
    643.57/964.37 = 426.69/x
  3. Step 3: Cross multiply
    643.57x = 964.37 × 426.69
  4. Step 4: Simplify right side
    643.57x = 411,488.10
  5. Step 5: Solve for x
    x = 411,488.10/643.57
  6. Step 6: Final answer
    x = 639.39

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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.