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Finding the Fourth Proportional to 121.57, 182.72 and 81.25

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Solution

The fourth proportional to 121.57, 182.72 and 81.25 is: 122.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.57 : 182.72 = 81.25 : x
  2. Step 2: Convert to fraction form
    121.57/182.72 = 81.25/x
  3. Step 3: Cross multiply
    121.57x = 182.72 × 81.25
  4. Step 4: Simplify right side
    121.57x = 14,845.75
  5. Step 5: Solve for x
    x = 14,845.75/121.57
  6. Step 6: Final answer
    x = 122.12

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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.