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Finding the Fourth Proportional to 427.08, 639.90 and 253.56

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Solution

The fourth proportional to 427.08, 639.90 and 253.56 is: 379.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.08 : 639.90 = 253.56 : x
  2. Step 2: Convert to fraction form
    427.08/639.90 = 253.56/x
  3. Step 3: Cross multiply
    427.08x = 639.90 × 253.56
  4. Step 4: Simplify right side
    427.08x = 162,253.04
  5. Step 5: Solve for x
    x = 162,253.04/427.08
  6. Step 6: Final answer
    x = 379.91

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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.