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Finding the Fourth Proportional to 219.56, 328.78 and 138.16

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Solution

The fourth proportional to 219.56, 328.78 and 138.16 is: 206.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.56 : 328.78 = 138.16 : x
  2. Step 2: Convert to fraction form
    219.56/328.78 = 138.16/x
  3. Step 3: Cross multiply
    219.56x = 328.78 × 138.16
  4. Step 4: Simplify right side
    219.56x = 45,424.24
  5. Step 5: Solve for x
    x = 45,424.24/219.56
  6. Step 6: Final answer
    x = 206.89

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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.