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Finding the Fourth Proportional to 428.08, 641.35 and 312.27

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Solution

The fourth proportional to 428.08, 641.35 and 312.27 is: 467.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.08 : 641.35 = 312.27 : x
  2. Step 2: Convert to fraction form
    428.08/641.35 = 312.27/x
  3. Step 3: Cross multiply
    428.08x = 641.35 × 312.27
  4. Step 4: Simplify right side
    428.08x = 200,274.36
  5. Step 5: Solve for x
    x = 200,274.36/428.08
  6. Step 6: Final answer
    x = 467.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.