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Finding the Fourth Proportional to 311.38, 429.70 and 180.40

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Solution

The fourth proportional to 311.38, 429.70 and 180.40 is: 248.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.38 : 429.70 = 180.40 : x
  2. Step 2: Convert to fraction form
    311.38/429.70 = 180.40/x
  3. Step 3: Cross multiply
    311.38x = 429.70 × 180.40
  4. Step 4: Simplify right side
    311.38x = 77,517.88
  5. Step 5: Solve for x
    x = 77,517.88/311.38
  6. Step 6: Final answer
    x = 248.95

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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.