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Finding the Fourth Proportional to 108.62, 162.77 and 85.70

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Solution

The fourth proportional to 108.62, 162.77 and 85.70 is: 128.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.62 : 162.77 = 85.70 : x
  2. Step 2: Convert to fraction form
    108.62/162.77 = 85.70/x
  3. Step 3: Cross multiply
    108.62x = 162.77 × 85.70
  4. Step 4: Simplify right side
    108.62x = 13,948.96
  5. Step 5: Solve for x
    x = 13,948.96/108.62
  6. Step 6: Final answer
    x = 128.42

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.