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Finding the Fourth Proportional to 311.51, 432.86 and 308.13

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Solution

The fourth proportional to 311.51, 432.86 and 308.13 is: 428.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.51 : 432.86 = 308.13 : x
  2. Step 2: Convert to fraction form
    311.51/432.86 = 308.13/x
  3. Step 3: Cross multiply
    311.51x = 432.86 × 308.13
  4. Step 4: Simplify right side
    311.51x = 133,375.61
  5. Step 5: Solve for x
    x = 133,375.61/311.51
  6. Step 6: Final answer
    x = 428.17

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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.