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Finding the Fourth Proportional to 205.95, 308.37 and 128.82

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Solution

The fourth proportional to 205.95, 308.37 and 128.82 is: 192.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.95 : 308.37 = 128.82 : x
  2. Step 2: Convert to fraction form
    205.95/308.37 = 128.82/x
  3. Step 3: Cross multiply
    205.95x = 308.37 × 128.82
  4. Step 4: Simplify right side
    205.95x = 39,724.22
  5. Step 5: Solve for x
    x = 39,724.22/205.95
  6. Step 6: Final answer
    x = 192.88

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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.