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Finding the Fourth Proportional to 643.52, 887.69 and 394.65

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Solution

The fourth proportional to 643.52, 887.69 and 394.65 is: 544.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.52 : 887.69 = 394.65 : x
  2. Step 2: Convert to fraction form
    643.52/887.69 = 394.65/x
  3. Step 3: Cross multiply
    643.52x = 887.69 × 394.65
  4. Step 4: Simplify right side
    643.52x = 350,327.85
  5. Step 5: Solve for x
    x = 350,327.85/643.52
  6. Step 6: Final answer
    x = 544.39

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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.