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Finding the Fourth Proportional to 426.56, 639.69 and 253.28

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Solution

The fourth proportional to 426.56, 639.69 and 253.28 is: 379.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.56 : 639.69 = 253.28 : x
  2. Step 2: Convert to fraction form
    426.56/639.69 = 253.28/x
  3. Step 3: Cross multiply
    426.56x = 639.69 × 253.28
  4. Step 4: Simplify right side
    426.56x = 162,020.68
  5. Step 5: Solve for x
    x = 162,020.68/426.56
  6. Step 6: Final answer
    x = 379.83

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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.