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Finding the Fourth Proportional to 121.76, 168.05 and 77.54

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Solution

The fourth proportional to 121.76, 168.05 and 77.54 is: 107.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.76 : 168.05 = 77.54 : x
  2. Step 2: Convert to fraction form
    121.76/168.05 = 77.54/x
  3. Step 3: Cross multiply
    121.76x = 168.05 × 77.54
  4. Step 4: Simplify right side
    121.76x = 13,030.60
  5. Step 5: Solve for x
    x = 13,030.60/121.76
  6. Step 6: Final answer
    x = 107.02

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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.