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Finding the Third Proportional to 217.50 and 309.25

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Solution

The third proportional to 217.50 and 309.25 is: 439.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    217.50 : 309.25 = 309.25 : x
  2. Step 2: Convert to fraction form
    217.50/309.25 = 309.25/x
  3. Step 3: Cross multiply
    217.50x = 309.25 × 309.25
  4. Step 4: Simplify right side
    217.50x = 95,635.56
  5. Step 5: Solve for x
    x = 95,635.56/217.50
  6. Step 6: Final answer
    x = 439.70

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Why These Related Problems?

These problems maintain the same ratio (1.42) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.