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Finding the Fourth Proportional to 645.75, 968.90 and 213.08

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Solution

The fourth proportional to 645.75, 968.90 and 213.08 is: 319.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.75 : 968.90 = 213.08 : x
  2. Step 2: Convert to fraction form
    645.75/968.90 = 213.08/x
  3. Step 3: Cross multiply
    645.75x = 968.90 × 213.08
  4. Step 4: Simplify right side
    645.75x = 206,447.30
  5. Step 5: Solve for x
    x = 206,447.30/645.75
  6. Step 6: Final answer
    x = 319.70

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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.