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Finding the Fourth Proportional to 219.79, 329.32 and 128.44

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Solution

The fourth proportional to 219.79, 329.32 and 128.44 is: 192.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    219.79 : 329.32 = 128.44 : x
  2. Step 2: Convert to fraction form
    219.79/329.32 = 128.44/x
  3. Step 3: Cross multiply
    219.79x = 329.32 × 128.44
  4. Step 4: Simplify right side
    219.79x = 42,297.86
  5. Step 5: Solve for x
    x = 42,297.86/219.79
  6. Step 6: Final answer
    x = 192.45

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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.