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Finding the Fourth Proportional to 121.38, 182.20 and 75.81

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Solution

The fourth proportional to 121.38, 182.20 and 75.81 is: 113.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.38 : 182.20 = 75.81 : x
  2. Step 2: Convert to fraction form
    121.38/182.20 = 75.81/x
  3. Step 3: Cross multiply
    121.38x = 182.20 × 75.81
  4. Step 4: Simplify right side
    121.38x = 13,812.58
  5. Step 5: Solve for x
    x = 13,812.58/121.38
  6. Step 6: Final answer
    x = 113.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.