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Finding the Fourth Proportional to 426.08, 639.25 and 220.79

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Solution

The fourth proportional to 426.08, 639.25 and 220.79 is: 331.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.08 : 639.25 = 220.79 : x
  2. Step 2: Convert to fraction form
    426.08/639.25 = 220.79/x
  3. Step 3: Cross multiply
    426.08x = 639.25 × 220.79
  4. Step 4: Simplify right side
    426.08x = 141,140.01
  5. Step 5: Solve for x
    x = 141,140.01/426.08
  6. Step 6: Final answer
    x = 331.25

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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.