Home / 1,120.20-1,679.40-389.76

Finding the Fourth Proportional to 1,120.20, 1,679.40 and 389.76

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Solution

The fourth proportional to 1,120.20, 1,679.40 and 389.76 is: 584.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.20 : 1,679.40 = 389.76 : x
  2. Step 2: Convert to fraction form
    1,120.20/1,679.40 = 389.76/x
  3. Step 3: Cross multiply
    1,120.20x = 1,679.40 × 389.76
  4. Step 4: Simplify right side
    1,120.20x = 654,562.94
  5. Step 5: Solve for x
    x = 654,562.94/1,120.20
  6. Step 6: Final answer
    x = 584.33

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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.