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Finding the Fourth Proportional to 121.34, 181.97 and 77.85

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Solution

The fourth proportional to 121.34, 181.97 and 77.85 is: 116.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.34 : 181.97 = 77.85 : x
  2. Step 2: Convert to fraction form
    121.34/181.97 = 77.85/x
  3. Step 3: Cross multiply
    121.34x = 181.97 × 77.85
  4. Step 4: Simplify right side
    121.34x = 14,165.98
  5. Step 5: Solve for x
    x = 14,165.98/121.34
  6. Step 6: Final answer
    x = 116.75

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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.