Home / 1,280.20-1,920.30-1,272.10

Finding the Fourth Proportional to 1,280.20, 1,920.30 and 1,272.10

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Solution

The fourth proportional to 1,280.20, 1,920.30 and 1,272.10 is: 1,908.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.20 : 1,920.30 = 1,272.10 : x
  2. Step 2: Convert to fraction form
    1,280.20/1,920.30 = 1,272.10/x
  3. Step 3: Cross multiply
    1,280.20x = 1,920.30 × 1,272.10
  4. Step 4: Simplify right side
    1,280.20x = 2,442,813.63
  5. Step 5: Solve for x
    x = 2,442,813.63/1,280.20
  6. Step 6: Final answer
    x = 1,908.15

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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.