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Finding the Fourth Proportional to 645.38, 968.09 and 212.57

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Solution

The fourth proportional to 645.38, 968.09 and 212.57 is: 318.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.38 : 968.09 = 212.57 : x
  2. Step 2: Convert to fraction form
    645.38/968.09 = 212.57/x
  3. Step 3: Cross multiply
    645.38x = 968.09 × 212.57
  4. Step 4: Simplify right side
    645.38x = 205,780.99
  5. Step 5: Solve for x
    x = 205,780.99/645.38
  6. Step 6: Final answer
    x = 318.85

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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.