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Finding the Fourth Proportional to 168.30, 252.21 and 87.20

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Solution

The fourth proportional to 168.30, 252.21 and 87.20 is: 130.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    168.30 : 252.21 = 87.20 : x
  2. Step 2: Convert to fraction form
    168.30/252.21 = 87.20/x
  3. Step 3: Cross multiply
    168.30x = 252.21 × 87.20
  4. Step 4: Simplify right side
    168.30x = 21,993.43
  5. Step 5: Solve for x
    x = 21,993.43/168.30
  6. Step 6: Final answer
    x = 130.68

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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.