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Finding the Third Proportional to 821.25 and 1,800

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Solution

The third proportional to 821.25 and 1,800 is: 3,945.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.25 : 1,800 = 1,800 : x
  2. Step 2: Convert to fraction form
    821.25/1,800 = 1,800/x
  3. Step 3: Cross multiply
    821.25x = 1,800 × 1,800
  4. Step 4: Simplify right side
    821.25x = 3,240,000
  5. Step 5: Solve for x
    x = 3,240,000/821.25
  6. Step 6: Final answer
    x = 3,945.21

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Why These Related Problems?

These problems maintain the same ratio (2.19) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.