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Finding the Fourth Proportional to 420.25, 629.79 and 159.98

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Solution

The fourth proportional to 420.25, 629.79 and 159.98 is: 239.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.25 : 629.79 = 159.98 : x
  2. Step 2: Convert to fraction form
    420.25/629.79 = 159.98/x
  3. Step 3: Cross multiply
    420.25x = 629.79 × 159.98
  4. Step 4: Simplify right side
    420.25x = 100,753.80
  5. Step 5: Solve for x
    x = 100,753.80/420.25
  6. Step 6: Final answer
    x = 239.75

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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.