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Finding the Fourth Proportional to 311.83, 430.05 and 256.25

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Solution

The fourth proportional to 311.83, 430.05 and 256.25 is: 353.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    311.83 : 430.05 = 256.25 : x
  2. Step 2: Convert to fraction form
    311.83/430.05 = 256.25/x
  3. Step 3: Cross multiply
    311.83x = 430.05 × 256.25
  4. Step 4: Simplify right side
    311.83x = 110,198.80
  5. Step 5: Solve for x
    x = 110,198.80/311.83
  6. Step 6: Final answer
    x = 353.39

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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.