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Finding the Third Proportional to 840.38 and 1,290.38

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Solution

The third proportional to 840.38 and 1,290.38 is: 1,981.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.38 : 1,290.38 = 1,290.38 : x
  2. Step 2: Convert to fraction form
    840.38/1,290.38 = 1,290.38/x
  3. Step 3: Cross multiply
    840.38x = 1,290.38 × 1,290.38
  4. Step 4: Simplify right side
    840.38x = 1,665,067.64
  5. Step 5: Solve for x
    x = 1,665,067.64/840.38
  6. Step 6: Final answer
    x = 1,981.34

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Why These Related Problems?

These problems maintain the same ratio (1.54) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.