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Finding the Fourth Proportional to 121.30, 181.85 and 119.78

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Solution

The fourth proportional to 121.30, 181.85 and 119.78 is: 179.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.30 : 181.85 = 119.78 : x
  2. Step 2: Convert to fraction form
    121.30/181.85 = 119.78/x
  3. Step 3: Cross multiply
    121.30x = 181.85 × 119.78
  4. Step 4: Simplify right side
    121.30x = 21,781.17
  5. Step 5: Solve for x
    x = 21,781.17/121.30
  6. Step 6: Final answer
    x = 179.57

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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.