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Finding the Fourth Proportional to 219.40, 329.28 and 138.28

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Solution

The fourth proportional to 219.40, 329.28 and 138.28 is: 207.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.40 : 329.28 = 138.28 : x
  2. Step 2: Convert to fraction form
    219.40/329.28 = 138.28/x
  3. Step 3: Cross multiply
    219.40x = 329.28 × 138.28
  4. Step 4: Simplify right side
    219.40x = 45,532.84
  5. Step 5: Solve for x
    x = 45,532.84/219.40
  6. Step 6: Final answer
    x = 207.53

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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.