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Finding the Fourth Proportional to 120.67, 181.01 and 86.50

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Solution

The fourth proportional to 120.67, 181.01 and 86.50 is: 129.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.67 : 181.01 = 86.50 : x
  2. Step 2: Convert to fraction form
    120.67/181.01 = 86.50/x
  3. Step 3: Cross multiply
    120.67x = 181.01 × 86.50
  4. Step 4: Simplify right side
    120.67x = 15,657.56
  5. Step 5: Solve for x
    x = 15,657.56/120.67
  6. Step 6: Final answer
    x = 129.75

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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.