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Finding the Fourth Proportional to 121.15, 167.07 and 77.50

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Solution

The fourth proportional to 121.15, 167.07 and 77.50 is: 106.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    121.15 : 167.07 = 77.50 : x
  2. Step 2: Convert to fraction form
    121.15/167.07 = 77.50/x
  3. Step 3: Cross multiply
    121.15x = 167.07 × 77.50
  4. Step 4: Simplify right side
    121.15x = 12,947.93
  5. Step 5: Solve for x
    x = 12,947.93/121.15
  6. Step 6: Final answer
    x = 106.88

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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.