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Finding the Fourth Proportional to 419.39, 629.09 and 145.42

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Solution

The fourth proportional to 419.39, 629.09 and 145.42 is: 218.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.39 : 629.09 = 145.42 : x
  2. Step 2: Convert to fraction form
    419.39/629.09 = 145.42/x
  3. Step 3: Cross multiply
    419.39x = 629.09 × 145.42
  4. Step 4: Simplify right side
    419.39x = 91,479.42
  5. Step 5: Solve for x
    x = 91,479.42/419.39
  6. Step 6: Final answer
    x = 218.12

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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.