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Finding the Fourth Proportional to 419.72, 628.61 and 405.13

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Solution

The fourth proportional to 419.72, 628.61 and 405.13 is: 606.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    419.72 : 628.61 = 405.13 : x
  2. Step 2: Convert to fraction form
    419.72/628.61 = 405.13/x
  3. Step 3: Cross multiply
    419.72x = 628.61 × 405.13
  4. Step 4: Simplify right side
    419.72x = 254,667.87
  5. Step 5: Solve for x
    x = 254,667.87/419.72
  6. Step 6: Final answer
    x = 606.75

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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.