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Finding the Fourth Proportional to 161.80, 242.85 and 80.71

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Solution

The fourth proportional to 161.80, 242.85 and 80.71 is: 121.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    161.80 : 242.85 = 80.71 : x
  2. Step 2: Convert to fraction form
    161.80/242.85 = 80.71/x
  3. Step 3: Cross multiply
    161.80x = 242.85 × 80.71
  4. Step 4: Simplify right side
    161.80x = 19,600.42
  5. Step 5: Solve for x
    x = 19,600.42/161.80
  6. Step 6: Final answer
    x = 121.14

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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.