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Finding the Third Proportional to 390.38 and 840.94

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Solution

The third proportional to 390.38 and 840.94 is: 1,811.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.38 : 840.94 = 840.94 : x
  2. Step 2: Convert to fraction form
    390.38/840.94 = 840.94/x
  3. Step 3: Cross multiply
    390.38x = 840.94 × 840.94
  4. Step 4: Simplify right side
    390.38x = 707,175.88
  5. Step 5: Solve for x
    x = 707,175.88/390.38
  6. Step 6: Final answer
    x = 1,811.53

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Why These Related Problems?

These problems maintain the same ratio (2.15) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.