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Finding the Fourth Proportional to 121.68, 181.29 and 115.56

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Solution

The fourth proportional to 121.68, 181.29 and 115.56 is: 172.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.68 : 181.29 = 115.56 : x
  2. Step 2: Convert to fraction form
    121.68/181.29 = 115.56/x
  3. Step 3: Cross multiply
    121.68x = 181.29 × 115.56
  4. Step 4: Simplify right side
    121.68x = 20,949.87
  5. Step 5: Solve for x
    x = 20,949.87/121.68
  6. Step 6: Final answer
    x = 172.17

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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.