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Finding the Fourth Proportional to 121.86, 181.32 and 121.45

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Solution

The fourth proportional to 121.86, 181.32 and 121.45 is: 180.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.86 : 181.32 = 121.45 : x
  2. Step 2: Convert to fraction form
    121.86/181.32 = 121.45/x
  3. Step 3: Cross multiply
    121.86x = 181.32 × 121.45
  4. Step 4: Simplify right side
    121.86x = 22,021.46
  5. Step 5: Solve for x
    x = 22,021.46/121.86
  6. Step 6: Final answer
    x = 180.71

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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.