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Finding the Fourth Proportional to 108.54, 149.70 and 99.81

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Solution

The fourth proportional to 108.54, 149.70 and 99.81 is: 137.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.54 : 149.70 = 99.81 : x
  2. Step 2: Convert to fraction form
    108.54/149.70 = 99.81/x
  3. Step 3: Cross multiply
    108.54x = 149.70 × 99.81
  4. Step 4: Simplify right side
    108.54x = 14,940.95
  5. Step 5: Solve for x
    x = 14,940.95/108.54
  6. Step 6: Final answer
    x = 137.65

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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.