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Finding the Fourth Proportional to 213.56, 320.22 and 128.12

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Solution

The fourth proportional to 213.56, 320.22 and 128.12 is: 192.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    213.56 : 320.22 = 128.12 : x
  2. Step 2: Convert to fraction form
    213.56/320.22 = 128.12/x
  3. Step 3: Cross multiply
    213.56x = 320.22 × 128.12
  4. Step 4: Simplify right side
    213.56x = 41,026.59
  5. Step 5: Solve for x
    x = 41,026.59/213.56
  6. Step 6: Final answer
    x = 192.11

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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.