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Finding the Fourth Proportional to 840.11, 1,260.09 and 320.09

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Solution

The fourth proportional to 840.11, 1,260.09 and 320.09 is: 480.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.11 : 1,260.09 = 320.09 : x
  2. Step 2: Convert to fraction form
    840.11/1,260.09 = 320.09/x
  3. Step 3: Cross multiply
    840.11x = 1,260.09 × 320.09
  4. Step 4: Simplify right side
    840.11x = 403,335.91
  5. Step 5: Solve for x
    x = 403,335.91/840.11
  6. Step 6: Final answer
    x = 480.10

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.