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Finding the Fourth Proportional to 205.21, 283.12 and 138.91

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Solution

The fourth proportional to 205.21, 283.12 and 138.91 is: 191.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.21 : 283.12 = 138.91 : x
  2. Step 2: Convert to fraction form
    205.21/283.12 = 138.91/x
  3. Step 3: Cross multiply
    205.21x = 283.12 × 138.91
  4. Step 4: Simplify right side
    205.21x = 39,328.07
  5. Step 5: Solve for x
    x = 39,328.07/205.21
  6. Step 6: Final answer
    x = 191.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.