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Finding the Fourth Proportional to 420.54, 627.38 and 409.20

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Solution

The fourth proportional to 420.54, 627.38 and 409.20 is: 610.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.54 : 627.38 = 409.20 : x
  2. Step 2: Convert to fraction form
    420.54/627.38 = 409.20/x
  3. Step 3: Cross multiply
    420.54x = 627.38 × 409.20
  4. Step 4: Simplify right side
    420.54x = 256,721.85
  5. Step 5: Solve for x
    x = 256,721.85/420.54
  6. Step 6: Final answer
    x = 610.46

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.