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Finding the Fourth Proportional to 426.41, 639.18 and 221.07

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Solution

The fourth proportional to 426.41, 639.18 and 221.07 is: 331.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.41 : 639.18 = 221.07 : x
  2. Step 2: Convert to fraction form
    426.41/639.18 = 221.07/x
  3. Step 3: Cross multiply
    426.41x = 639.18 × 221.07
  4. Step 4: Simplify right side
    426.41x = 141,303.52
  5. Step 5: Solve for x
    x = 141,303.52/426.41
  6. Step 6: Final answer
    x = 331.38

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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.