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Finding the Fourth Proportional to 420.69, 629.47 and 255.54

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Solution

The fourth proportional to 420.69, 629.47 and 255.54 is: 382.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.69 : 629.47 = 255.54 : x
  2. Step 2: Convert to fraction form
    420.69/629.47 = 255.54/x
  3. Step 3: Cross multiply
    420.69x = 629.47 × 255.54
  4. Step 4: Simplify right side
    420.69x = 160,854.76
  5. Step 5: Solve for x
    x = 160,854.76/420.69
  6. Step 6: Final answer
    x = 382.36

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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.