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Finding the Fourth Proportional to 428.42, 639.26 and 402.30

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Solution

The fourth proportional to 428.42, 639.26 and 402.30 is: 600.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.42 : 639.26 = 402.30 : x
  2. Step 2: Convert to fraction form
    428.42/639.26 = 402.30/x
  3. Step 3: Cross multiply
    428.42x = 639.26 × 402.30
  4. Step 4: Simplify right side
    428.42x = 257,171.10
  5. Step 5: Solve for x
    x = 257,171.10/428.42
  6. Step 6: Final answer
    x = 600.28

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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.