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Finding the Fourth Proportional to 642.78, 963.36 and 423.27

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Solution

The fourth proportional to 642.78, 963.36 and 423.27 is: 634.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.78 : 963.36 = 423.27 : x
  2. Step 2: Convert to fraction form
    642.78/963.36 = 423.27/x
  3. Step 3: Cross multiply
    642.78x = 963.36 × 423.27
  4. Step 4: Simplify right side
    642.78x = 407,761.39
  5. Step 5: Solve for x
    x = 407,761.39/642.78
  6. Step 6: Final answer
    x = 634.37

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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.