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Finding the Fourth Proportional to 121.38, 181.54 and 69.90

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Solution

The fourth proportional to 121.38, 181.54 and 69.90 is: 104.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.38 : 181.54 = 69.90 : x
  2. Step 2: Convert to fraction form
    121.38/181.54 = 69.90/x
  3. Step 3: Cross multiply
    121.38x = 181.54 × 69.90
  4. Step 4: Simplify right side
    121.38x = 12,689.05
  5. Step 5: Solve for x
    x = 12,689.05/121.38
  6. Step 6: Final answer
    x = 104.54

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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.