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Finding the Fourth Proportional to 209.69, 289.26 and 126.80

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Solution

The fourth proportional to 209.69, 289.26 and 126.80 is: 174.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.69 : 289.26 = 126.80 : x
  2. Step 2: Convert to fraction form
    209.69/289.26 = 126.80/x
  3. Step 3: Cross multiply
    209.69x = 289.26 × 126.80
  4. Step 4: Simplify right side
    209.69x = 36,676.72
  5. Step 5: Solve for x
    x = 36,676.72/209.69
  6. Step 6: Final answer
    x = 174.91

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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.