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Finding the Fourth Proportional to 86.16, 119.64 and 85.44

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Solution

The fourth proportional to 86.16, 119.64 and 85.44 is: 118.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.16 : 119.64 = 85.44 : x
  2. Step 2: Convert to fraction form
    86.16/119.64 = 85.44/x
  3. Step 3: Cross multiply
    86.16x = 119.64 × 85.44
  4. Step 4: Simplify right side
    86.16x = 10,222.04
  5. Step 5: Solve for x
    x = 10,222.04/86.16
  6. Step 6: Final answer
    x = 118.64

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.