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Finding the Fourth Proportional to 426.39, 639.12 and 243.38

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Solution

The fourth proportional to 426.39, 639.12 and 243.38 is: 364.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.39 : 639.12 = 243.38 : x
  2. Step 2: Convert to fraction form
    426.39/639.12 = 243.38/x
  3. Step 3: Cross multiply
    426.39x = 639.12 × 243.38
  4. Step 4: Simplify right side
    426.39x = 155,549.41
  5. Step 5: Solve for x
    x = 155,549.41/426.39
  6. Step 6: Final answer
    x = 364.80

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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.