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Finding the Fourth Proportional to 645.64, 966.84 and 428.56

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Solution

The fourth proportional to 645.64, 966.84 and 428.56 is: 641.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.64 : 966.84 = 428.56 : x
  2. Step 2: Convert to fraction form
    645.64/966.84 = 428.56/x
  3. Step 3: Cross multiply
    645.64x = 966.84 × 428.56
  4. Step 4: Simplify right side
    645.64x = 414,348.95
  5. Step 5: Solve for x
    x = 414,348.95/645.64
  6. Step 6: Final answer
    x = 641.76

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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.