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Finding the Fourth Proportional to 121.89, 181.97 and 107.21

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Solution

The fourth proportional to 121.89, 181.97 and 107.21 is: 160.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.89 : 181.97 = 107.21 : x
  2. Step 2: Convert to fraction form
    121.89/181.97 = 107.21/x
  3. Step 3: Cross multiply
    121.89x = 181.97 × 107.21
  4. Step 4: Simplify right side
    121.89x = 19,509.00
  5. Step 5: Solve for x
    x = 19,509.00/121.89
  6. Step 6: Final answer
    x = 160.05

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.