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Finding the Fourth Proportional to 420.07, 629.98 and 127.56

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Solution

The fourth proportional to 420.07, 629.98 and 127.56 is: 191.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.07 : 629.98 = 127.56 : x
  2. Step 2: Convert to fraction form
    420.07/629.98 = 127.56/x
  3. Step 3: Cross multiply
    420.07x = 629.98 × 127.56
  4. Step 4: Simplify right side
    420.07x = 80,360.25
  5. Step 5: Solve for x
    x = 80,360.25/420.07
  6. Step 6: Final answer
    x = 191.30

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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.