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Finding the Fourth Proportional to 311.09, 429.28 and 171.21

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Solution

The fourth proportional to 311.09, 429.28 and 171.21 is: 236.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.09 : 429.28 = 171.21 : x
  2. Step 2: Convert to fraction form
    311.09/429.28 = 171.21/x
  3. Step 3: Cross multiply
    311.09x = 429.28 × 171.21
  4. Step 4: Simplify right side
    311.09x = 73,497.03
  5. Step 5: Solve for x
    x = 73,497.03/311.09
  6. Step 6: Final answer
    x = 236.26

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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.