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Finding the Fourth Proportional to 120.98, 181.16 and 66.81

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Solution

The fourth proportional to 120.98, 181.16 and 66.81 is: 100.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.98 : 181.16 = 66.81 : x
  2. Step 2: Convert to fraction form
    120.98/181.16 = 66.81/x
  3. Step 3: Cross multiply
    120.98x = 181.16 × 66.81
  4. Step 4: Simplify right side
    120.98x = 12,102.97
  5. Step 5: Solve for x
    x = 12,102.97/120.98
  6. Step 6: Final answer
    x = 100.05

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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.