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Finding the Fourth Proportional to 645.70, 968.28 and 212.80

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Solution

The fourth proportional to 645.70, 968.28 and 212.80 is: 319.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.70 : 968.28 = 212.80 : x
  2. Step 2: Convert to fraction form
    645.70/968.28 = 212.80/x
  3. Step 3: Cross multiply
    645.70x = 968.28 × 212.80
  4. Step 4: Simplify right side
    645.70x = 206,049.98
  5. Step 5: Solve for x
    x = 206,049.98/645.70
  6. Step 6: Final answer
    x = 319.11

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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.