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Finding the Fourth Proportional to 311.45, 429.71 and 213.30

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Solution

The fourth proportional to 311.45, 429.71 and 213.30 is: 294.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.45 : 429.71 = 213.30 : x
  2. Step 2: Convert to fraction form
    311.45/429.71 = 213.30/x
  3. Step 3: Cross multiply
    311.45x = 429.71 × 213.30
  4. Step 4: Simplify right side
    311.45x = 91,656.08
  5. Step 5: Solve for x
    x = 91,656.08/311.45
  6. Step 6: Final answer
    x = 294.29

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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.