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Finding the Fourth Proportional to 86.39, 129.45 and 64.62

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Solution

The fourth proportional to 86.39, 129.45 and 64.62 is: 96.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.39 : 129.45 = 64.62 : x
  2. Step 2: Convert to fraction form
    86.39/129.45 = 64.62/x
  3. Step 3: Cross multiply
    86.39x = 129.45 × 64.62
  4. Step 4: Simplify right side
    86.39x = 8,365.30
  5. Step 5: Solve for x
    x = 8,365.30/86.39
  6. Step 6: Final answer
    x = 96.83

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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.