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Finding the Fourth Proportional to 121.38, 181.86 and 90.96

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Solution

The fourth proportional to 121.38, 181.86 and 90.96 is: 136.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.38 : 181.86 = 90.96 : x
  2. Step 2: Convert to fraction form
    121.38/181.86 = 90.96/x
  3. Step 3: Cross multiply
    121.38x = 181.86 × 90.96
  4. Step 4: Simplify right side
    121.38x = 16,541.99
  5. Step 5: Solve for x
    x = 16,541.99/121.38
  6. Step 6: Final answer
    x = 136.28

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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.