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Finding the Fourth Proportional to 420.33, 629.11 and 405.75

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Solution

The fourth proportional to 420.33, 629.11 and 405.75 is: 607.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.33 : 629.11 = 405.75 : x
  2. Step 2: Convert to fraction form
    420.33/629.11 = 405.75/x
  3. Step 3: Cross multiply
    420.33x = 629.11 × 405.75
  4. Step 4: Simplify right side
    420.33x = 255,261.38
  5. Step 5: Solve for x
    x = 255,261.38/420.33
  6. Step 6: Final answer
    x = 607.29

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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.