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Finding the Fourth Proportional to 220.72, 330.78 and 172.64

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Solution

The fourth proportional to 220.72, 330.78 and 172.64 is: 258.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    220.72 : 330.78 = 172.64 : x
  2. Step 2: Convert to fraction form
    220.72/330.78 = 172.64/x
  3. Step 3: Cross multiply
    220.72x = 330.78 × 172.64
  4. Step 4: Simplify right side
    220.72x = 57,105.86
  5. Step 5: Solve for x
    x = 57,105.86/220.72
  6. Step 6: Final answer
    x = 258.73

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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.