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Finding the Fourth Proportional to 454.31, 678.18 and 420.50

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Solution

The fourth proportional to 454.31, 678.18 and 420.50 is: 627.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    454.31 : 678.18 = 420.50 : x
  2. Step 2: Convert to fraction form
    454.31/678.18 = 420.50/x
  3. Step 3: Cross multiply
    454.31x = 678.18 × 420.50
  4. Step 4: Simplify right side
    454.31x = 285,171.30
  5. Step 5: Solve for x
    x = 285,171.30/454.31
  6. Step 6: Final answer
    x = 627.71

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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.