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Finding the Fourth Proportional to 419.70, 629.89 and 214.40

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Solution

The fourth proportional to 419.70, 629.89 and 214.40 is: 321.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.70 : 629.89 = 214.40 : x
  2. Step 2: Convert to fraction form
    419.70/629.89 = 214.40/x
  3. Step 3: Cross multiply
    419.70x = 629.89 × 214.40
  4. Step 4: Simplify right side
    419.70x = 135,049.45
  5. Step 5: Solve for x
    x = 135,049.45/419.70
  6. Step 6: Final answer
    x = 321.78

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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.