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Finding the Fourth Proportional to 205.67, 308.79 and 128.41

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Solution

The fourth proportional to 205.67, 308.79 and 128.41 is: 192.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.67 : 308.79 = 128.41 : x
  2. Step 2: Convert to fraction form
    205.67/308.79 = 128.41/x
  3. Step 3: Cross multiply
    205.67x = 308.79 × 128.41
  4. Step 4: Simplify right side
    205.67x = 39,650.95
  5. Step 5: Solve for x
    x = 39,650.95/205.67
  6. Step 6: Final answer
    x = 192.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.