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Finding the Fourth Proportional to 86.12, 128.89 and 63.29

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Solution

The fourth proportional to 86.12, 128.89 and 63.29 is: 94.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.12 : 128.89 = 63.29 : x
  2. Step 2: Convert to fraction form
    86.12/128.89 = 63.29/x
  3. Step 3: Cross multiply
    86.12x = 128.89 × 63.29
  4. Step 4: Simplify right side
    86.12x = 8,157.45
  5. Step 5: Solve for x
    x = 8,157.45/86.12
  6. Step 6: Final answer
    x = 94.72

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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.