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Finding the Fourth Proportional to 86.73, 119.62 and 65.78

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Solution

The fourth proportional to 86.73, 119.62 and 65.78 is: 90.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.73 : 119.62 = 65.78 : x
  2. Step 2: Convert to fraction form
    86.73/119.62 = 65.78/x
  3. Step 3: Cross multiply
    86.73x = 119.62 × 65.78
  4. Step 4: Simplify right side
    86.73x = 7,867.68
  5. Step 5: Solve for x
    x = 7,867.68/86.73
  6. Step 6: Final answer
    x = 90.71

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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.