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Finding the Fourth Proportional to 121.09, 181.49 and 47.89

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Solution

The fourth proportional to 121.09, 181.49 and 47.89 is: 71.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.09 : 181.49 = 47.89 : x
  2. Step 2: Convert to fraction form
    121.09/181.49 = 47.89/x
  3. Step 3: Cross multiply
    121.09x = 181.49 × 47.89
  4. Step 4: Simplify right side
    121.09x = 8,692.13
  5. Step 5: Solve for x
    x = 8,692.13/121.09
  6. Step 6: Final answer
    x = 71.79

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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.