Home / 1,120.11-1,680.20-389.72

Finding the Fourth Proportional to 1,120.11, 1,680.20 and 389.72

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Solution

The fourth proportional to 1,120.11, 1,680.20 and 389.72 is: 584.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,120.11 : 1,680.20 = 389.72 : x
  2. Step 2: Convert to fraction form
    1,120.11/1,680.20 = 389.72/x
  3. Step 3: Cross multiply
    1,120.11x = 1,680.20 × 389.72
  4. Step 4: Simplify right side
    1,120.11x = 654,797.19
  5. Step 5: Solve for x
    x = 654,797.19/1,120.11
  6. Step 6: Final answer
    x = 584.58

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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.