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Finding the Third Proportional to 636.19 and 691.31

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Solution

The third proportional to 636.19 and 691.31 is: 751.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.19 : 691.31 = 691.31 : x
  2. Step 2: Convert to fraction form
    636.19/691.31 = 691.31/x
  3. Step 3: Cross multiply
    636.19x = 691.31 × 691.31
  4. Step 4: Simplify right side
    636.19x = 477,912.97
  5. Step 5: Solve for x
    x = 477,912.97/636.19
  6. Step 6: Final answer
    x = 751.21

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Why These Related Problems?

These problems maintain the same ratio (1.09) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.