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Finding the Fourth Proportional to 209.70, 289.32 and 126.81

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Solution

The fourth proportional to 209.70, 289.32 and 126.81 is: 174.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.70 : 289.32 = 126.81 : x
  2. Step 2: Convert to fraction form
    209.70/289.32 = 126.81/x
  3. Step 3: Cross multiply
    209.70x = 289.32 × 126.81
  4. Step 4: Simplify right side
    209.70x = 36,688.67
  5. Step 5: Solve for x
    x = 36,688.67/209.70
  6. Step 6: Final answer
    x = 174.96

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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.