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Finding the Fourth Proportional to 219.81, 330.17 and 138.71

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Solution

The fourth proportional to 219.81, 330.17 and 138.71 is: 208.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.81 : 330.17 = 138.71 : x
  2. Step 2: Convert to fraction form
    219.81/330.17 = 138.71/x
  3. Step 3: Cross multiply
    219.81x = 330.17 × 138.71
  4. Step 4: Simplify right side
    219.81x = 45,796.23
  5. Step 5: Solve for x
    x = 45,796.23/219.81
  6. Step 6: Final answer
    x = 208.35

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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.