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Finding the Third Proportional to 258.19 and 408.38

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Solution

The third proportional to 258.19 and 408.38 is: 645.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    258.19 : 408.38 = 408.38 : x
  2. Step 2: Convert to fraction form
    258.19/408.38 = 408.38/x
  3. Step 3: Cross multiply
    258.19x = 408.38 × 408.38
  4. Step 4: Simplify right side
    258.19x = 166,770.14
  5. Step 5: Solve for x
    x = 166,770.14/258.19
  6. Step 6: Final answer
    x = 645.93

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Why These Related Problems?

These problems maintain the same ratio (1.58) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.