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Finding the Fourth Proportional to 311.68, 430.56 and 308.68

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Solution

The fourth proportional to 311.68, 430.56 and 308.68 is: 426.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.68 : 430.56 = 308.68 : x
  2. Step 2: Convert to fraction form
    311.68/430.56 = 308.68/x
  3. Step 3: Cross multiply
    311.68x = 430.56 × 308.68
  4. Step 4: Simplify right side
    311.68x = 132,905.26
  5. Step 5: Solve for x
    x = 132,905.26/311.68
  6. Step 6: Final answer
    x = 426.42

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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.