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Finding the Fourth Proportional to 840.39, 1,260.81 and 255.36

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Solution

The fourth proportional to 840.39, 1,260.81 and 255.36 is: 383.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.39 : 1,260.81 = 255.36 : x
  2. Step 2: Convert to fraction form
    840.39/1,260.81 = 255.36/x
  3. Step 3: Cross multiply
    840.39x = 1,260.81 × 255.36
  4. Step 4: Simplify right side
    840.39x = 321,960.44
  5. Step 5: Solve for x
    x = 321,960.44/840.39
  6. Step 6: Final answer
    x = 383.11

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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.