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Finding the Fourth Proportional to 311.36, 432.55 and 308.51

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Solution

The fourth proportional to 311.36, 432.55 and 308.51 is: 428.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.36 : 432.55 = 308.51 : x
  2. Step 2: Convert to fraction form
    311.36/432.55 = 308.51/x
  3. Step 3: Cross multiply
    311.36x = 432.55 × 308.51
  4. Step 4: Simplify right side
    311.36x = 133,443.07
  5. Step 5: Solve for x
    x = 133,443.07/311.36
  6. Step 6: Final answer
    x = 428.59

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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.