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Finding the Fourth Proportional to 642.24, 963.28 and 427.12

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Solution

The fourth proportional to 642.24, 963.28 and 427.12 is: 640.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.24 : 963.28 = 427.12 : x
  2. Step 2: Convert to fraction form
    642.24/963.28 = 427.12/x
  3. Step 3: Cross multiply
    642.24x = 963.28 × 427.12
  4. Step 4: Simplify right side
    642.24x = 411,436.15
  5. Step 5: Solve for x
    x = 411,436.15/642.24
  6. Step 6: Final answer
    x = 640.63

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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.