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Finding the Third Proportional to 390.66 and 843.09

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Solution

The third proportional to 390.66 and 843.09 is: 1,819.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.66 : 843.09 = 843.09 : x
  2. Step 2: Convert to fraction form
    390.66/843.09 = 843.09/x
  3. Step 3: Cross multiply
    390.66x = 843.09 × 843.09
  4. Step 4: Simplify right side
    390.66x = 710,807.07
  5. Step 5: Solve for x
    x = 710,807.07/390.66
  6. Step 6: Final answer
    x = 1,819.52

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Why These Related Problems?

These problems maintain the same ratio (2.16) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.