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Finding the Fourth Proportional to 87.17, 120.38 and 74.65

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Solution

The fourth proportional to 87.17, 120.38 and 74.65 is: 103.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.17 : 120.38 = 74.65 : x
  2. Step 2: Convert to fraction form
    87.17/120.38 = 74.65/x
  3. Step 3: Cross multiply
    87.17x = 120.38 × 74.65
  4. Step 4: Simplify right side
    87.17x = 8,986.85
  5. Step 5: Solve for x
    x = 8,986.85/87.17
  6. Step 6: Final answer
    x = 103.09

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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.