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Finding the Third Proportional to 390 and 477

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Solution

The third proportional to 390 and 477 is: 583.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    390 : 477 = 477 : x
  2. Step 2: Convert to fraction form
    390/477 = 477/x
  3. Step 3: Cross multiply
    390x = 477 × 477
  4. Step 4: Simplify right side
    390x = 227,529
  5. Step 5: Solve for x
    x = 227,529/390
  6. Step 6: Final answer
    x = 583.41

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Why These Related Problems?

These problems maintain the same ratio (1.22) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.