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Finding the Fourth Proportional to 209.90, 289.67 and 122.60

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Solution

The fourth proportional to 209.90, 289.67 and 122.60 is: 169.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.90 : 289.67 = 122.60 : x
  2. Step 2: Convert to fraction form
    209.90/289.67 = 122.60/x
  3. Step 3: Cross multiply
    209.90x = 289.67 × 122.60
  4. Step 4: Simplify right side
    209.90x = 35,511.48
  5. Step 5: Solve for x
    x = 35,511.48/209.90
  6. Step 6: Final answer
    x = 169.19

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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.