Home / 1,390.20-2,081.70-1,099.80

Finding the Fourth Proportional to 1,390.20, 2,081.70 and 1,099.80

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Solution

The fourth proportional to 1,390.20, 2,081.70 and 1,099.80 is: 1,646.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,390.20 : 2,081.70 = 1,099.80 : x
  2. Step 2: Convert to fraction form
    1,390.20/2,081.70 = 1,099.80/x
  3. Step 3: Cross multiply
    1,390.20x = 2,081.70 × 1,099.80
  4. Step 4: Simplify right side
    1,390.20x = 2,289,453.66
  5. Step 5: Solve for x
    x = 2,289,453.66/1,390.20
  6. Step 6: Final answer
    x = 1,646.85

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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.