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Finding the Fourth Proportional to 108.40, 149.55 and 66.91

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Solution

The fourth proportional to 108.40, 149.55 and 66.91 is: 92.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.40 : 149.55 = 66.91 : x
  2. Step 2: Convert to fraction form
    108.40/149.55 = 66.91/x
  3. Step 3: Cross multiply
    108.40x = 149.55 × 66.91
  4. Step 4: Simplify right side
    108.40x = 10,006.39
  5. Step 5: Solve for x
    x = 10,006.39/108.40
  6. Step 6: Final answer
    x = 92.31

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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.