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Finding the Fourth Proportional to 86.05, 118.79 and 61.65

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Solution

The fourth proportional to 86.05, 118.79 and 61.65 is: 85.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.05 : 118.79 = 61.65 : x
  2. Step 2: Convert to fraction form
    86.05/118.79 = 61.65/x
  3. Step 3: Cross multiply
    86.05x = 118.79 × 61.65
  4. Step 4: Simplify right side
    86.05x = 7,323.56
  5. Step 5: Solve for x
    x = 7,323.56/86.05
  6. Step 6: Final answer
    x = 85.11

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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.