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Finding the Fourth Proportional to 121.83, 168.09 and 72.06

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Solution

The fourth proportional to 121.83, 168.09 and 72.06 is: 99.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.83 : 168.09 = 72.06 : x
  2. Step 2: Convert to fraction form
    121.83/168.09 = 72.06/x
  3. Step 3: Cross multiply
    121.83x = 168.09 × 72.06
  4. Step 4: Simplify right side
    121.83x = 12,112.57
  5. Step 5: Solve for x
    x = 12,112.57/121.83
  6. Step 6: Final answer
    x = 99.42

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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.