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Finding the Fourth Proportional to 855.20, 1,285.20 and 749.60

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Solution

The fourth proportional to 855.20, 1,285.20 and 749.60 is: 1,126.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.20 : 1,285.20 = 749.60 : x
  2. Step 2: Convert to fraction form
    855.20/1,285.20 = 749.60/x
  3. Step 3: Cross multiply
    855.20x = 1,285.20 × 749.60
  4. Step 4: Simplify right side
    855.20x = 963,385.92
  5. Step 5: Solve for x
    x = 963,385.92/855.20
  6. Step 6: Final answer
    x = 1,126.50

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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.