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Finding the Fourth Proportional to 121.31, 181.62 and 109.16

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Solution

The fourth proportional to 121.31, 181.62 and 109.16 is: 163.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.31 : 181.62 = 109.16 : x
  2. Step 2: Convert to fraction form
    121.31/181.62 = 109.16/x
  3. Step 3: Cross multiply
    121.31x = 181.62 × 109.16
  4. Step 4: Simplify right side
    121.31x = 19,824.73
  5. Step 5: Solve for x
    x = 19,824.73/121.31
  6. Step 6: Final answer
    x = 163.43

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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.