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Finding the Fourth Proportional to 86.05, 129.67 and 81.93

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Solution

The fourth proportional to 86.05, 129.67 and 81.93 is: 123.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.05 : 129.67 = 81.93 : x
  2. Step 2: Convert to fraction form
    86.05/129.67 = 81.93/x
  3. Step 3: Cross multiply
    86.05x = 129.67 × 81.93
  4. Step 4: Simplify right side
    86.05x = 10,623.86
  5. Step 5: Solve for x
    x = 10,623.86/86.05
  6. Step 6: Final answer
    x = 123.46

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.