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Finding the Fourth Proportional to 428.64, 642.24 and 265.92

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Solution

The fourth proportional to 428.64, 642.24 and 265.92 is: 398.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.64 : 642.24 = 265.92 : x
  2. Step 2: Convert to fraction form
    428.64/642.24 = 265.92/x
  3. Step 3: Cross multiply
    428.64x = 642.24 × 265.92
  4. Step 4: Simplify right side
    428.64x = 170,784.46
  5. Step 5: Solve for x
    x = 170,784.46/428.64
  6. Step 6: Final answer
    x = 398.43

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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.