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Finding the Third Proportional to 398 and 440

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Solution

The third proportional to 398 and 440 is: 486.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    398 : 440 = 440 : x
  2. Step 2: Convert to fraction form
    398/440 = 440/x
  3. Step 3: Cross multiply
    398x = 440 × 440
  4. Step 4: Simplify right side
    398x = 193,600
  5. Step 5: Solve for x
    x = 193,600/398
  6. Step 6: Final answer
    x = 486.43

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Why These Related Problems?

These problems maintain the same ratio (1.11) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.