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Finding the Fourth Proportional to 999.56, 1,379.09 and 789.77

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Solution

The fourth proportional to 999.56, 1,379.09 and 789.77 is: 1,089.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.56 : 1,379.09 = 789.77 : x
  2. Step 2: Convert to fraction form
    999.56/1,379.09 = 789.77/x
  3. Step 3: Cross multiply
    999.56x = 1,379.09 × 789.77
  4. Step 4: Simplify right side
    999.56x = 1,089,169.33
  5. Step 5: Solve for x
    x = 1,089,169.33/999.56
  6. Step 6: Final answer
    x = 1,089.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.