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Finding the Fourth Proportional to 643.20, 956.92 and 641.04

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Solution

The fourth proportional to 643.20, 956.92 and 641.04 is: 953.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.20 : 956.92 = 641.04 : x
  2. Step 2: Convert to fraction form
    643.20/956.92 = 641.04/x
  3. Step 3: Cross multiply
    643.20x = 956.92 × 641.04
  4. Step 4: Simplify right side
    643.20x = 613,424.00
  5. Step 5: Solve for x
    x = 613,424.00/643.20
  6. Step 6: Final answer
    x = 953.71

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.