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Finding the Fourth Proportional to 120.81, 181.31 and 84.77

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Solution

The fourth proportional to 120.81, 181.31 and 84.77 is: 127.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.81 : 181.31 = 84.77 : x
  2. Step 2: Convert to fraction form
    120.81/181.31 = 84.77/x
  3. Step 3: Cross multiply
    120.81x = 181.31 × 84.77
  4. Step 4: Simplify right side
    120.81x = 15,369.65
  5. Step 5: Solve for x
    x = 15,369.65/120.81
  6. Step 6: Final answer
    x = 127.22

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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.