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Finding the Fourth Proportional to 120.82, 181.21 and 55.80

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Solution

The fourth proportional to 120.82, 181.21 and 55.80 is: 83.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.82 : 181.21 = 55.80 : x
  2. Step 2: Convert to fraction form
    120.82/181.21 = 55.80/x
  3. Step 3: Cross multiply
    120.82x = 181.21 × 55.80
  4. Step 4: Simplify right side
    120.82x = 10,111.52
  5. Step 5: Solve for x
    x = 10,111.52/120.82
  6. Step 6: Final answer
    x = 83.69

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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.