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Finding the Fourth Proportional to 209.72, 312.58 and 205.67

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Solution

The fourth proportional to 209.72, 312.58 and 205.67 is: 306.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.72 : 312.58 = 205.67 : x
  2. Step 2: Convert to fraction form
    209.72/312.58 = 205.67/x
  3. Step 3: Cross multiply
    209.72x = 312.58 × 205.67
  4. Step 4: Simplify right side
    209.72x = 64,288.33
  5. Step 5: Solve for x
    x = 64,288.33/209.72
  6. Step 6: Final answer
    x = 306.54

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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.