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Finding the Fourth Proportional to 161.20, 220.85 and 155.05

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Solution

The fourth proportional to 161.20, 220.85 and 155.05 is: 212.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.20 : 220.85 = 155.05 : x
  2. Step 2: Convert to fraction form
    161.20/220.85 = 155.05/x
  3. Step 3: Cross multiply
    161.20x = 220.85 × 155.05
  4. Step 4: Simplify right side
    161.20x = 34,242.79
  5. Step 5: Solve for x
    x = 34,242.79/161.20
  6. Step 6: Final answer
    x = 212.42

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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.