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Finding the Fourth Proportional to 645.28, 966.61 and 425.21

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Solution

The fourth proportional to 645.28, 966.61 and 425.21 is: 636.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.28 : 966.61 = 425.21 : x
  2. Step 2: Convert to fraction form
    645.28/966.61 = 425.21/x
  3. Step 3: Cross multiply
    645.28x = 966.61 × 425.21
  4. Step 4: Simplify right side
    645.28x = 411,013.54
  5. Step 5: Solve for x
    x = 411,013.54/645.28
  6. Step 6: Final answer
    x = 636.95

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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.