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Finding the Fourth Proportional to 399.61, 550.15 and 379.09

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Solution

The fourth proportional to 399.61, 550.15 and 379.09 is: 521.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.61 : 550.15 = 379.09 : x
  2. Step 2: Convert to fraction form
    399.61/550.15 = 379.09/x
  3. Step 3: Cross multiply
    399.61x = 550.15 × 379.09
  4. Step 4: Simplify right side
    399.61x = 208,556.36
  5. Step 5: Solve for x
    x = 208,556.36/399.61
  6. Step 6: Final answer
    x = 521.90

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.