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Finding the Fourth Proportional to 311.78, 433.07 and 306.81

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Solution

The fourth proportional to 311.78, 433.07 and 306.81 is: 426.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.78 : 433.07 = 306.81 : x
  2. Step 2: Convert to fraction form
    311.78/433.07 = 306.81/x
  3. Step 3: Cross multiply
    311.78x = 433.07 × 306.81
  4. Step 4: Simplify right side
    311.78x = 132,870.21
  5. Step 5: Solve for x
    x = 132,870.21/311.78
  6. Step 6: Final answer
    x = 426.17

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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.