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Finding the Fourth Proportional to 420.12, 627.01 and 409.20

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Solution

The fourth proportional to 420.12, 627.01 and 409.20 is: 610.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.12 : 627.01 = 409.20 : x
  2. Step 2: Convert to fraction form
    420.12/627.01 = 409.20/x
  3. Step 3: Cross multiply
    420.12x = 627.01 × 409.20
  4. Step 4: Simplify right side
    420.12x = 256,572.49
  5. Step 5: Solve for x
    x = 256,572.49/420.12
  6. Step 6: Final answer
    x = 610.71

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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.