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Finding the Fourth Proportional to 86.15, 119.43 and 84.87

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Solution

The fourth proportional to 86.15, 119.43 and 84.87 is: 117.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.15 : 119.43 = 84.87 : x
  2. Step 2: Convert to fraction form
    86.15/119.43 = 84.87/x
  3. Step 3: Cross multiply
    86.15x = 119.43 × 84.87
  4. Step 4: Simplify right side
    86.15x = 10,136.02
  5. Step 5: Solve for x
    x = 10,136.02/86.15
  6. Step 6: Final answer
    x = 117.66

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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.