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Finding the Third Proportional to 398.67 and 620.79

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Solution

The third proportional to 398.67 and 620.79 is: 966.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    398.67 : 620.79 = 620.79 : x
  2. Step 2: Convert to fraction form
    398.67/620.79 = 620.79/x
  3. Step 3: Cross multiply
    398.67x = 620.79 × 620.79
  4. Step 4: Simplify right side
    398.67x = 385,379.06
  5. Step 5: Solve for x
    x = 385,379.06/398.67
  6. Step 6: Final answer
    x = 966.66

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Why These Related Problems?

These problems maintain the same ratio (1.56) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.