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Finding the Fourth Proportional to 420.23, 629.36 and 405.63

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Solution

The fourth proportional to 420.23, 629.36 and 405.63 is: 607.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.23 : 629.36 = 405.63 : x
  2. Step 2: Convert to fraction form
    420.23/629.36 = 405.63/x
  3. Step 3: Cross multiply
    420.23x = 629.36 × 405.63
  4. Step 4: Simplify right side
    420.23x = 255,287.30
  5. Step 5: Solve for x
    x = 255,287.30/420.23
  6. Step 6: Final answer
    x = 607.50

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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.