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Finding the Fourth Proportional to 120.80, 181.09 and 39.60

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Solution

The fourth proportional to 120.80, 181.09 and 39.60 is: 59.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.80 : 181.09 = 39.60 : x
  2. Step 2: Convert to fraction form
    120.80/181.09 = 39.60/x
  3. Step 3: Cross multiply
    120.80x = 181.09 × 39.60
  4. Step 4: Simplify right side
    120.80x = 7,171.16
  5. Step 5: Solve for x
    x = 7,171.16/120.80
  6. Step 6: Final answer
    x = 59.36

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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.