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Finding the Fourth Proportional to 161.21, 222.60 and 128.61

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Solution

The fourth proportional to 161.21, 222.60 and 128.61 is: 177.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.21 : 222.60 = 128.61 : x
  2. Step 2: Convert to fraction form
    161.21/222.60 = 128.61/x
  3. Step 3: Cross multiply
    161.21x = 222.60 × 128.61
  4. Step 4: Simplify right side
    161.21x = 28,628.59
  5. Step 5: Solve for x
    x = 28,628.59/161.21
  6. Step 6: Final answer
    x = 177.59

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.