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Finding the Fourth Proportional to 426.69, 639.87 and 253.39

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Solution

The fourth proportional to 426.69, 639.87 and 253.39 is: 379.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    426.69 : 639.87 = 253.39 : x
  2. Step 2: Convert to fraction form
    426.69/639.87 = 253.39/x
  3. Step 3: Cross multiply
    426.69x = 639.87 × 253.39
  4. Step 4: Simplify right side
    426.69x = 162,136.66
  5. Step 5: Solve for x
    x = 162,136.66/426.69
  6. Step 6: Final answer
    x = 379.99

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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.