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Finding the Third Proportional to 311 and 380

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Solution

The third proportional to 311 and 380 is: 464.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    311 : 380 = 380 : x
  2. Step 2: Convert to fraction form
    311/380 = 380/x
  3. Step 3: Cross multiply
    311x = 380 × 380
  4. Step 4: Simplify right side
    311x = 144,400
  5. Step 5: Solve for x
    x = 144,400/311
  6. Step 6: Final answer
    x = 464.31

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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.