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Finding the Fourth Proportional to 419.78, 629.52 and 145.85

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Solution

The fourth proportional to 419.78, 629.52 and 145.85 is: 218.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.78 : 629.52 = 145.85 : x
  2. Step 2: Convert to fraction form
    419.78/629.52 = 145.85/x
  3. Step 3: Cross multiply
    419.78x = 629.52 × 145.85
  4. Step 4: Simplify right side
    419.78x = 91,815.49
  5. Step 5: Solve for x
    x = 91,815.49/419.78
  6. Step 6: Final answer
    x = 218.72

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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.