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Finding the Fourth Proportional to 645.65, 968.38 and 212.75

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Solution

The fourth proportional to 645.65, 968.38 and 212.75 is: 319.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.65 : 968.38 = 212.75 : x
  2. Step 2: Convert to fraction form
    645.65/968.38 = 212.75/x
  3. Step 3: Cross multiply
    645.65x = 968.38 × 212.75
  4. Step 4: Simplify right side
    645.65x = 206,022.85
  5. Step 5: Solve for x
    x = 206,022.85/645.65
  6. Step 6: Final answer
    x = 319.09

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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.