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Finding the Fourth Proportional to 121.83, 181.78 and 111.39

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Solution

The fourth proportional to 121.83, 181.78 and 111.39 is: 166.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.83 : 181.78 = 111.39 : x
  2. Step 2: Convert to fraction form
    121.83/181.78 = 111.39/x
  3. Step 3: Cross multiply
    121.83x = 181.78 × 111.39
  4. Step 4: Simplify right side
    121.83x = 20,248.20
  5. Step 5: Solve for x
    x = 20,248.20/121.83
  6. Step 6: Final answer
    x = 166.20

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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.