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Finding the Fourth Proportional to 209.67, 289.30 and 126.78

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Solution

The fourth proportional to 209.67, 289.30 and 126.78 is: 174.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.67 : 289.30 = 126.78 : x
  2. Step 2: Convert to fraction form
    209.67/289.30 = 126.78/x
  3. Step 3: Cross multiply
    209.67x = 289.30 × 126.78
  4. Step 4: Simplify right side
    209.67x = 36,675.37
  5. Step 5: Solve for x
    x = 36,675.37/209.67
  6. Step 6: Final answer
    x = 174.92

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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.