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Finding the Fourth Proportional to 1,280.15, 1,920.31 and 539.61

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Solution

The fourth proportional to 1,280.15, 1,920.31 and 539.61 is: 809.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.15 : 1,920.31 = 539.61 : x
  2. Step 2: Convert to fraction form
    1,280.15/1,920.31 = 539.61/x
  3. Step 3: Cross multiply
    1,280.15x = 1,920.31 × 539.61
  4. Step 4: Simplify right side
    1,280.15x = 1,036,220.73
  5. Step 5: Solve for x
    x = 1,036,220.73/1,280.15
  6. Step 6: Final answer
    x = 809.45

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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.