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Finding the Fourth Proportional to 120.72, 181.16 and 66.65

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Solution

The fourth proportional to 120.72, 181.16 and 66.65 is: 100.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.72 : 181.16 = 66.65 : x
  2. Step 2: Convert to fraction form
    120.72/181.16 = 66.65/x
  3. Step 3: Cross multiply
    120.72x = 181.16 × 66.65
  4. Step 4: Simplify right side
    120.72x = 12,074.31
  5. Step 5: Solve for x
    x = 12,074.31/120.72
  6. Step 6: Final answer
    x = 100.02

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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.