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Finding the Fourth Proportional to 122.60, 169.14 and 89.78

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Solution

The fourth proportional to 122.60, 169.14 and 89.78 is: 123.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    122.60 : 169.14 = 89.78 : x
  2. Step 2: Convert to fraction form
    122.60/169.14 = 89.78/x
  3. Step 3: Cross multiply
    122.60x = 169.14 × 89.78
  4. Step 4: Simplify right side
    122.60x = 15,185.39
  5. Step 5: Solve for x
    x = 15,185.39/122.60
  6. Step 6: Final answer
    x = 123.86

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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.