Home / 1,081.20-1,621.97-387.72

Finding the Fourth Proportional to 1,081.20, 1,621.97 and 387.72

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Solution

The fourth proportional to 1,081.20, 1,621.97 and 387.72 is: 581.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,081.20 : 1,621.97 = 387.72 : x
  2. Step 2: Convert to fraction form
    1,081.20/1,621.97 = 387.72/x
  3. Step 3: Cross multiply
    1,081.20x = 1,621.97 × 387.72
  4. Step 4: Simplify right side
    1,081.20x = 628,870.21
  5. Step 5: Solve for x
    x = 628,870.21/1,081.20
  6. Step 6: Final answer
    x = 581.64

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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.