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Finding the Fourth Proportional to 420.50, 629.82 and 408.98

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Solution

The fourth proportional to 420.50, 629.82 and 408.98 is: 612.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.50 : 629.82 = 408.98 : x
  2. Step 2: Convert to fraction form
    420.50/629.82 = 408.98/x
  3. Step 3: Cross multiply
    420.50x = 629.82 × 408.98
  4. Step 4: Simplify right side
    420.50x = 257,583.78
  5. Step 5: Solve for x
    x = 257,583.78/420.50
  6. Step 6: Final answer
    x = 612.57

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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.