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Finding the Fourth Proportional to 86.81, 129.90 and 50.57

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Solution

The fourth proportional to 86.81, 129.90 and 50.57 is: 75.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.81 : 129.90 = 50.57 : x
  2. Step 2: Convert to fraction form
    86.81/129.90 = 50.57/x
  3. Step 3: Cross multiply
    86.81x = 129.90 × 50.57
  4. Step 4: Simplify right side
    86.81x = 6,568.39
  5. Step 5: Solve for x
    x = 6,568.39/86.81
  6. Step 6: Final answer
    x = 75.66

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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.