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Finding the Fourth Proportional to 840.87, 1,261.13 and 255.74

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Solution

The fourth proportional to 840.87, 1,261.13 and 255.74 is: 383.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.87 : 1,261.13 = 255.74 : x
  2. Step 2: Convert to fraction form
    840.87/1,261.13 = 255.74/x
  3. Step 3: Cross multiply
    840.87x = 1,261.13 × 255.74
  4. Step 4: Simplify right side
    840.87x = 322,523.26
  5. Step 5: Solve for x
    x = 322,523.26/840.87
  6. Step 6: Final answer
    x = 383.56

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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.