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Finding the Third Proportional to 420.19 and 628.31

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Solution

The third proportional to 420.19 and 628.31 is: 939.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.19 : 628.31 = 628.31 : x
  2. Step 2: Convert to fraction form
    420.19/628.31 = 628.31/x
  3. Step 3: Cross multiply
    420.19x = 628.31 × 628.31
  4. Step 4: Simplify right side
    420.19x = 394,776.60
  5. Step 5: Solve for x
    x = 394,776.60/420.19
  6. Step 6: Final answer
    x = 939.52

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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.