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Finding the Fourth Proportional to 419.46, 629.21 and 256.78

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Solution

The fourth proportional to 419.46, 629.21 and 256.78 is: 385.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.46 : 629.21 = 256.78 : x
  2. Step 2: Convert to fraction form
    419.46/629.21 = 256.78/x
  3. Step 3: Cross multiply
    419.46x = 629.21 × 256.78
  4. Step 4: Simplify right side
    419.46x = 161,568.54
  5. Step 5: Solve for x
    x = 161,568.54/419.46
  6. Step 6: Final answer
    x = 385.18

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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.