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Finding the Fourth Proportional to 86.28, 129.41 and 51.59

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Solution

The fourth proportional to 86.28, 129.41 and 51.59 is: 77.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.28 : 129.41 = 51.59 : x
  2. Step 2: Convert to fraction form
    86.28/129.41 = 51.59/x
  3. Step 3: Cross multiply
    86.28x = 129.41 × 51.59
  4. Step 4: Simplify right side
    86.28x = 6,675.68
  5. Step 5: Solve for x
    x = 6,675.68/86.28
  6. Step 6: Final answer
    x = 77.37

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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.