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Finding the Fourth Proportional to 855.21, 1,280.49 and 545.39

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Solution

The fourth proportional to 855.21, 1,280.49 and 545.39 is: 816.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    855.21 : 1,280.49 = 545.39 : x
  2. Step 2: Convert to fraction form
    855.21/1,280.49 = 545.39/x
  3. Step 3: Cross multiply
    855.21x = 1,280.49 × 545.39
  4. Step 4: Simplify right side
    855.21x = 698,366.44
  5. Step 5: Solve for x
    x = 698,366.44/855.21
  6. Step 6: Final answer
    x = 816.60

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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.