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Finding the Fourth Proportional to 86.72, 119.64 and 67.28

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Solution

The fourth proportional to 86.72, 119.64 and 67.28 is: 92.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.72 : 119.64 = 67.28 : x
  2. Step 2: Convert to fraction form
    86.72/119.64 = 67.28/x
  3. Step 3: Cross multiply
    86.72x = 119.64 × 67.28
  4. Step 4: Simplify right side
    86.72x = 8,049.38
  5. Step 5: Solve for x
    x = 8,049.38/86.72
  6. Step 6: Final answer
    x = 92.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.