Home / 1,121.22-1,679.67-939.78

Finding the Fourth Proportional to 1,121.22, 1,679.67 and 939.78

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Solution

The fourth proportional to 1,121.22, 1,679.67 and 939.78 is: 1,407.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,121.22 : 1,679.67 = 939.78 : x
  2. Step 2: Convert to fraction form
    1,121.22/1,679.67 = 939.78/x
  3. Step 3: Cross multiply
    1,121.22x = 1,679.67 × 939.78
  4. Step 4: Simplify right side
    1,121.22x = 1,578,520.27
  5. Step 5: Solve for x
    x = 1,578,520.27/1,121.22
  6. Step 6: Final answer
    x = 1,407.86

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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.