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Finding the Fourth Proportional to 121.62, 182.19 and 87.30

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Solution

The fourth proportional to 121.62, 182.19 and 87.30 is: 130.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.62 : 182.19 = 87.30 : x
  2. Step 2: Convert to fraction form
    121.62/182.19 = 87.30/x
  3. Step 3: Cross multiply
    121.62x = 182.19 × 87.30
  4. Step 4: Simplify right side
    121.62x = 15,905.19
  5. Step 5: Solve for x
    x = 15,905.19/121.62
  6. Step 6: Final answer
    x = 130.78

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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.