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Finding the Fourth Proportional to 209.40, 311.06 and 205.80

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Solution

The fourth proportional to 209.40, 311.06 and 205.80 is: 305.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.40 : 311.06 = 205.80 : x
  2. Step 2: Convert to fraction form
    209.40/311.06 = 205.80/x
  3. Step 3: Cross multiply
    209.40x = 311.06 × 205.80
  4. Step 4: Simplify right side
    209.40x = 64,016.15
  5. Step 5: Solve for x
    x = 64,016.15/209.40
  6. Step 6: Final answer
    x = 305.71

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.