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Finding the Fourth Proportional to 121.83, 168.30 and 86.97

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Solution

The fourth proportional to 121.83, 168.30 and 86.97 is: 120.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.83 : 168.30 = 86.97 : x
  2. Step 2: Convert to fraction form
    121.83/168.30 = 86.97/x
  3. Step 3: Cross multiply
    121.83x = 168.30 × 86.97
  4. Step 4: Simplify right side
    121.83x = 14,637.05
  5. Step 5: Solve for x
    x = 14,637.05/121.83
  6. Step 6: Final answer
    x = 120.14

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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.