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Finding the Third Proportional to 515 and 800

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Solution

The third proportional to 515 and 800 is: 1,242.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    515 : 800 = 800 : x
  2. Step 2: Convert to fraction form
    515/800 = 800/x
  3. Step 3: Cross multiply
    515x = 800 × 800
  4. Step 4: Simplify right side
    515x = 640,000
  5. Step 5: Solve for x
    x = 640,000/515
  6. Step 6: Final answer
    x = 1,242.72

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Why These Related Problems?

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