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Finding the Fourth Proportional to 108.21, 149.22 and 100.38

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Solution

The fourth proportional to 108.21, 149.22 and 100.38 is: 138.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.21 : 149.22 = 100.38 : x
  2. Step 2: Convert to fraction form
    108.21/149.22 = 100.38/x
  3. Step 3: Cross multiply
    108.21x = 149.22 × 100.38
  4. Step 4: Simplify right side
    108.21x = 14,978.70
  5. Step 5: Solve for x
    x = 14,978.70/108.21
  6. Step 6: Final answer
    x = 138.42

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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.