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Finding the Fourth Proportional to 72.21, 108.39 and 36.18

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Solution

The fourth proportional to 72.21, 108.39 and 36.18 is: 54.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.21 : 108.39 = 36.18 : x
  2. Step 2: Convert to fraction form
    72.21/108.39 = 36.18/x
  3. Step 3: Cross multiply
    72.21x = 108.39 × 36.18
  4. Step 4: Simplify right side
    72.21x = 3,921.55
  5. Step 5: Solve for x
    x = 3,921.55/72.21
  6. Step 6: Final answer
    x = 54.31

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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.