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Finding the Fourth Proportional to 642.40, 963.36 and 425.68

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Solution

The fourth proportional to 642.40, 963.36 and 425.68 is: 638.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.40 : 963.36 = 425.68 : x
  2. Step 2: Convert to fraction form
    642.40/963.36 = 425.68/x
  3. Step 3: Cross multiply
    642.40x = 963.36 × 425.68
  4. Step 4: Simplify right side
    642.40x = 410,083.08
  5. Step 5: Solve for x
    x = 410,083.08/642.40
  6. Step 6: Final answer
    x = 638.36

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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.