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Finding the Fourth Proportional to 87.95, 120.71 and 85.66

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Solution

The fourth proportional to 87.95, 120.71 and 85.66 is: 117.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.95 : 120.71 = 85.66 : x
  2. Step 2: Convert to fraction form
    87.95/120.71 = 85.66/x
  3. Step 3: Cross multiply
    87.95x = 120.71 × 85.66
  4. Step 4: Simplify right side
    87.95x = 10,339.45
  5. Step 5: Solve for x
    x = 10,339.45/87.95
  6. Step 6: Final answer
    x = 117.56

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.