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Finding the Third Proportional to 258 and 399

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Solution

The third proportional to 258 and 399 is: 617.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    258 : 399 = 399 : x
  2. Step 2: Convert to fraction form
    258/399 = 399/x
  3. Step 3: Cross multiply
    258x = 399 × 399
  4. Step 4: Simplify right side
    258x = 159,201
  5. Step 5: Solve for x
    x = 159,201/258
  6. Step 6: Final answer
    x = 617.06

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These problems maintain the same ratio (1.55) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.