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Finding the Fourth Proportional to 108.60, 149.86 and 64.90

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Solution

The fourth proportional to 108.60, 149.86 and 64.90 is: 89.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.60 : 149.86 = 64.90 : x
  2. Step 2: Convert to fraction form
    108.60/149.86 = 64.90/x
  3. Step 3: Cross multiply
    108.60x = 149.86 × 64.90
  4. Step 4: Simplify right side
    108.60x = 9,725.91
  5. Step 5: Solve for x
    x = 9,725.91/108.60
  6. Step 6: Final answer
    x = 89.56

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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.