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Finding the Fourth Proportional to 215.55, 323.24 and 87.21

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Solution

The fourth proportional to 215.55, 323.24 and 87.21 is: 130.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    215.55 : 323.24 = 87.21 : x
  2. Step 2: Convert to fraction form
    215.55/323.24 = 87.21/x
  3. Step 3: Cross multiply
    215.55x = 323.24 × 87.21
  4. Step 4: Simplify right side
    215.55x = 28,189.32
  5. Step 5: Solve for x
    x = 28,189.32/215.55
  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.