Home / 1,120.19-1,680.09-389.61

Finding the Fourth Proportional to 1,120.19, 1,680.09 and 389.61

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Solution

The fourth proportional to 1,120.19, 1,680.09 and 389.61 is: 584.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.19 : 1,680.09 = 389.61 : x
  2. Step 2: Convert to fraction form
    1,120.19/1,680.09 = 389.61/x
  3. Step 3: Cross multiply
    1,120.19x = 1,680.09 × 389.61
  4. Step 4: Simplify right side
    1,120.19x = 654,579.86
  5. Step 5: Solve for x
    x = 654,579.86/1,120.19
  6. Step 6: Final answer
    x = 584.35

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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.