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Finding the Fourth Proportional to 1,280.30, 1,920.45 and 1,231.70

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Solution

The fourth proportional to 1,280.30, 1,920.45 and 1,231.70 is: 1,847.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.30 : 1,920.45 = 1,231.70 : x
  2. Step 2: Convert to fraction form
    1,280.30/1,920.45 = 1,231.70/x
  3. Step 3: Cross multiply
    1,280.30x = 1,920.45 × 1,231.70
  4. Step 4: Simplify right side
    1,280.30x = 2,365,418.27
  5. Step 5: Solve for x
    x = 2,365,418.27/1,280.30
  6. Step 6: Final answer
    x = 1,847.55

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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.