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Finding the Fourth Proportional to 121.13, 180.82 and 105.75

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Solution

The fourth proportional to 121.13, 180.82 and 105.75 is: 157.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.13 : 180.82 = 105.75 : x
  2. Step 2: Convert to fraction form
    121.13/180.82 = 105.75/x
  3. Step 3: Cross multiply
    121.13x = 180.82 × 105.75
  4. Step 4: Simplify right side
    121.13x = 19,121.85
  5. Step 5: Solve for x
    x = 19,121.85/121.13
  6. Step 6: Final answer
    x = 157.86

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.