Home / 3,987-5,981.36-1,213.90

Finding the Fourth Proportional to 3,987, 5,981.36 and 1,213.90

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Solution

The fourth proportional to 3,987, 5,981.36 and 1,213.90 is: 1,821.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    3,987 : 5,981.36 = 1,213.90 : x
  2. Step 2: Convert to fraction form
    3,987/5,981.36 = 1,213.90/x
  3. Step 3: Cross multiply
    3,987x = 5,981.36 × 1,213.90
  4. Step 4: Simplify right side
    3,987x = 7,260,751.88
  5. Step 5: Solve for x
    x = 7,260,751.88/3,987
  6. Step 6: Final answer
    x = 1,821.11

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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.