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Finding the Fourth Proportional to 108.40, 149.58 and 86.68

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Solution

The fourth proportional to 108.40, 149.58 and 86.68 is: 119.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.40 : 149.58 = 86.68 : x
  2. Step 2: Convert to fraction form
    108.40/149.58 = 86.68/x
  3. Step 3: Cross multiply
    108.40x = 149.58 × 86.68
  4. Step 4: Simplify right side
    108.40x = 12,965.59
  5. Step 5: Solve for x
    x = 12,965.59/108.40
  6. Step 6: Final answer
    x = 119.61

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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.