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Finding the Fourth Proportional to 87.69, 121 and 50.85

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Solution

The fourth proportional to 87.69, 121 and 50.85 is: 70.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    87.69 : 121 = 50.85 : x
  2. Step 2: Convert to fraction form
    87.69/121 = 50.85/x
  3. Step 3: Cross multiply
    87.69x = 121 × 50.85
  4. Step 4: Simplify right side
    87.69x = 6,152.85
  5. Step 5: Solve for x
    x = 6,152.85/87.69
  6. Step 6: Final answer
    x = 70.17

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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.