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Finding the Fourth Proportional to 86.54, 129.14 and 77.46

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Solution

The fourth proportional to 86.54, 129.14 and 77.46 is: 115.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.54 : 129.14 = 77.46 : x
  2. Step 2: Convert to fraction form
    86.54/129.14 = 77.46/x
  3. Step 3: Cross multiply
    86.54x = 129.14 × 77.46
  4. Step 4: Simplify right side
    86.54x = 10,003.18
  5. Step 5: Solve for x
    x = 10,003.18/86.54
  6. Step 6: Final answer
    x = 115.59

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.