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Finding the Fourth Proportional to 154.50, 213.22 and 87.21

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Solution

The fourth proportional to 154.50, 213.22 and 87.21 is: 120.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.50 : 213.22 = 87.21 : x
  2. Step 2: Convert to fraction form
    154.50/213.22 = 87.21/x
  3. Step 3: Cross multiply
    154.50x = 213.22 × 87.21
  4. Step 4: Simplify right side
    154.50x = 18,594.92
  5. Step 5: Solve for x
    x = 18,594.92/154.50
  6. Step 6: Final answer
    x = 120.36

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.