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Finding the Fourth Proportional to 86.43, 129.64 and 30.83

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Solution

The fourth proportional to 86.43, 129.64 and 30.83 is: 46.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.43 : 129.64 = 30.83 : x
  2. Step 2: Convert to fraction form
    86.43/129.64 = 30.83/x
  3. Step 3: Cross multiply
    86.43x = 129.64 × 30.83
  4. Step 4: Simplify right side
    86.43x = 3,997.41
  5. Step 5: Solve for x
    x = 3,997.41/86.43
  6. Step 6: Final answer
    x = 46.25

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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.