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Finding the Fourth Proportional to 205.78, 308.64 and 140.71

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Solution

The fourth proportional to 205.78, 308.64 and 140.71 is: 211.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.78 : 308.64 = 140.71 : x
  2. Step 2: Convert to fraction form
    205.78/308.64 = 140.71/x
  3. Step 3: Cross multiply
    205.78x = 308.64 × 140.71
  4. Step 4: Simplify right side
    205.78x = 43,428.73
  5. Step 5: Solve for x
    x = 43,428.73/205.78
  6. Step 6: Final answer
    x = 211.04

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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.