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Finding the Fourth Proportional to 108.21, 149.07 and 90.61

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Solution

The fourth proportional to 108.21, 149.07 and 90.61 is: 124.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.21 : 149.07 = 90.61 : x
  2. Step 2: Convert to fraction form
    108.21/149.07 = 90.61/x
  3. Step 3: Cross multiply
    108.21x = 149.07 × 90.61
  4. Step 4: Simplify right side
    108.21x = 13,507.23
  5. Step 5: Solve for x
    x = 13,507.23/108.21
  6. Step 6: Final answer
    x = 124.82

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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.