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Finding the Fourth Proportional to 428.23, 587.11 and 420.45

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Solution

The fourth proportional to 428.23, 587.11 and 420.45 is: 576.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.23 : 587.11 = 420.45 : x
  2. Step 2: Convert to fraction form
    428.23/587.11 = 420.45/x
  3. Step 3: Cross multiply
    428.23x = 587.11 × 420.45
  4. Step 4: Simplify right side
    428.23x = 246,847.88
  5. Step 5: Solve for x
    x = 246,847.88/428.23
  6. Step 6: Final answer
    x = 576.43

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.