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Finding the Third Proportional to 318 and 407

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Solution

The third proportional to 318 and 407 is: 520.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    318 : 407 = 407 : x
  2. Step 2: Convert to fraction form
    318/407 = 407/x
  3. Step 3: Cross multiply
    318x = 407 × 407
  4. Step 4: Simplify right side
    318x = 165,649
  5. Step 5: Solve for x
    x = 165,649/318
  6. Step 6: Final answer
    x = 520.91

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These problems maintain the same ratio (1.28) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.