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Finding the Fourth Proportional to 121.40, 181.22 and 120.40

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Solution

The fourth proportional to 121.40, 181.22 and 120.40 is: 179.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.40 : 181.22 = 120.40 : x
  2. Step 2: Convert to fraction form
    121.40/181.22 = 120.40/x
  3. Step 3: Cross multiply
    121.40x = 181.22 × 120.40
  4. Step 4: Simplify right side
    121.40x = 21,818.89
  5. Step 5: Solve for x
    x = 21,818.89/121.40
  6. Step 6: Final answer
    x = 179.73

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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.