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Finding the Third Proportional to 399.75 and 638.06

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Solution

The third proportional to 399.75 and 638.06 is: 1,018.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.75 : 638.06 = 638.06 : x
  2. Step 2: Convert to fraction form
    399.75/638.06 = 638.06/x
  3. Step 3: Cross multiply
    399.75x = 638.06 × 638.06
  4. Step 4: Simplify right side
    399.75x = 407,123.75
  5. Step 5: Solve for x
    x = 407,123.75/399.75
  6. Step 6: Final answer
    x = 1,018.45

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These problems maintain the same ratio (1.60) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.