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Finding the Fourth Proportional to 153.70, 211.82 and 122.21

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Solution

The fourth proportional to 153.70, 211.82 and 122.21 is: 168.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    153.70 : 211.82 = 122.21 : x
  2. Step 2: Convert to fraction form
    153.70/211.82 = 122.21/x
  3. Step 3: Cross multiply
    153.70x = 211.82 × 122.21
  4. Step 4: Simplify right side
    153.70x = 25,885.65
  5. Step 5: Solve for x
    x = 25,885.65/153.70
  6. Step 6: Final answer
    x = 168.42

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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.