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Finding the Fourth Proportional to 121.69, 181.29 and 115.89

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Solution

The fourth proportional to 121.69, 181.29 and 115.89 is: 172.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.69 : 181.29 = 115.89 : x
  2. Step 2: Convert to fraction form
    121.69/181.29 = 115.89/x
  3. Step 3: Cross multiply
    121.69x = 181.29 × 115.89
  4. Step 4: Simplify right side
    121.69x = 21,009.70
  5. Step 5: Solve for x
    x = 21,009.70/121.69
  6. Step 6: Final answer
    x = 172.65

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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.