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Finding the Fourth Proportional to 161.55, 221.78 and 139.41

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Solution

The fourth proportional to 161.55, 221.78 and 139.41 is: 191.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.55 : 221.78 = 139.41 : x
  2. Step 2: Convert to fraction form
    161.55/221.78 = 139.41/x
  3. Step 3: Cross multiply
    161.55x = 221.78 × 139.41
  4. Step 4: Simplify right side
    161.55x = 30,918.70
  5. Step 5: Solve for x
    x = 30,918.70/161.55
  6. Step 6: Final answer
    x = 191.39

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.