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Finding the Fourth Proportional to 108.68, 149.84 and 85.40

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Solution

The fourth proportional to 108.68, 149.84 and 85.40 is: 117.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.68 : 149.84 = 85.40 : x
  2. Step 2: Convert to fraction form
    108.68/149.84 = 85.40/x
  3. Step 3: Cross multiply
    108.68x = 149.84 × 85.40
  4. Step 4: Simplify right side
    108.68x = 12,796.34
  5. Step 5: Solve for x
    x = 12,796.34/108.68
  6. Step 6: Final answer
    x = 117.74

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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.