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Finding the Fourth Proportional to 311.28, 429.75 and 213.18

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Solution

The fourth proportional to 311.28, 429.75 and 213.18 is: 294.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.28 : 429.75 = 213.18 : x
  2. Step 2: Convert to fraction form
    311.28/429.75 = 213.18/x
  3. Step 3: Cross multiply
    311.28x = 429.75 × 213.18
  4. Step 4: Simplify right side
    311.28x = 91,614.11
  5. Step 5: Solve for x
    x = 91,614.11/311.28
  6. Step 6: Final answer
    x = 294.31

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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.