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Finding the Fourth Proportional to 311.30, 431.36 and 307.38

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Solution

The fourth proportional to 311.30, 431.36 and 307.38 is: 425.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.30 : 431.36 = 307.38 : x
  2. Step 2: Convert to fraction form
    311.30/431.36 = 307.38/x
  3. Step 3: Cross multiply
    311.30x = 431.36 × 307.38
  4. Step 4: Simplify right side
    311.30x = 132,591.44
  5. Step 5: Solve for x
    x = 132,591.44/311.30
  6. Step 6: Final answer
    x = 425.93

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.