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Finding the Fourth Proportional to 121.80, 182.68 and 115.72

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Solution

The fourth proportional to 121.80, 182.68 and 115.72 is: 173.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.80 : 182.68 = 115.72 : x
  2. Step 2: Convert to fraction form
    121.80/182.68 = 115.72/x
  3. Step 3: Cross multiply
    121.80x = 182.68 × 115.72
  4. Step 4: Simplify right side
    121.80x = 21,139.73
  5. Step 5: Solve for x
    x = 21,139.73/121.80
  6. Step 6: Final answer
    x = 173.56

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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.