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Finding the Fourth Proportional to 318.20, 477.56 and 256.70

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Solution

The fourth proportional to 318.20, 477.56 and 256.70 is: 385.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    318.20 : 477.56 = 256.70 : x
  2. Step 2: Convert to fraction form
    318.20/477.56 = 256.70/x
  3. Step 3: Cross multiply
    318.20x = 477.56 × 256.70
  4. Step 4: Simplify right side
    318.20x = 122,589.65
  5. Step 5: Solve for x
    x = 122,589.65/318.20
  6. Step 6: Final answer
    x = 385.26

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.