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Finding the Fourth Proportional to 168.09, 231.69 and 121.55

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Solution

The fourth proportional to 168.09, 231.69 and 121.55 is: 167.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    168.09 : 231.69 = 121.55 : x
  2. Step 2: Convert to fraction form
    168.09/231.69 = 121.55/x
  3. Step 3: Cross multiply
    168.09x = 231.69 × 121.55
  4. Step 4: Simplify right side
    168.09x = 28,161.22
  5. Step 5: Solve for x
    x = 28,161.22/168.09
  6. Step 6: Final answer
    x = 167.54

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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.