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Finding the Fourth Proportional to 120.82, 181.21 and 43.78

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Solution

The fourth proportional to 120.82, 181.21 and 43.78 is: 65.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.82 : 181.21 = 43.78 : x
  2. Step 2: Convert to fraction form
    120.82/181.21 = 43.78/x
  3. Step 3: Cross multiply
    120.82x = 181.21 × 43.78
  4. Step 4: Simplify right side
    120.82x = 7,933.37
  5. Step 5: Solve for x
    x = 7,933.37/120.82
  6. Step 6: Final answer
    x = 65.66

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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.