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Finding the Fourth Proportional to 121.81, 182.55 and 87.56

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Solution

The fourth proportional to 121.81, 182.55 and 87.56 is: 131.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.81 : 182.55 = 87.56 : x
  2. Step 2: Convert to fraction form
    121.81/182.55 = 87.56/x
  3. Step 3: Cross multiply
    121.81x = 182.55 × 87.56
  4. Step 4: Simplify right side
    121.81x = 15,982.93
  5. Step 5: Solve for x
    x = 15,982.93/121.81
  6. Step 6: Final answer
    x = 131.21

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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.