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Finding the Fourth Proportional to 208.70, 312.92 and 161.78

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Solution

The fourth proportional to 208.70, 312.92 and 161.78 is: 242.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    208.70 : 312.92 = 161.78 : x
  2. Step 2: Convert to fraction form
    208.70/312.92 = 161.78/x
  3. Step 3: Cross multiply
    208.70x = 312.92 × 161.78
  4. Step 4: Simplify right side
    208.70x = 50,623.82
  5. Step 5: Solve for x
    x = 50,623.82/208.70
  6. Step 6: Final answer
    x = 242.57

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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.