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Finding the Fourth Proportional to 840.16, 1,260.55 and 255.21

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Solution

The fourth proportional to 840.16, 1,260.55 and 255.21 is: 382.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.16 : 1,260.55 = 255.21 : x
  2. Step 2: Convert to fraction form
    840.16/1,260.55 = 255.21/x
  3. Step 3: Cross multiply
    840.16x = 1,260.55 × 255.21
  4. Step 4: Simplify right side
    840.16x = 321,697.39
  5. Step 5: Solve for x
    x = 321,697.39/840.16
  6. Step 6: Final answer
    x = 382.90

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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.