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Finding the Fourth Proportional to 399.61, 551.79 and 379.23

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Solution

The fourth proportional to 399.61, 551.79 and 379.23 is: 523.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.61 : 551.79 = 379.23 : x
  2. Step 2: Convert to fraction form
    399.61/551.79 = 379.23/x
  3. Step 3: Cross multiply
    399.61x = 551.79 × 379.23
  4. Step 4: Simplify right side
    399.61x = 209,255.32
  5. Step 5: Solve for x
    x = 209,255.32/399.61
  6. Step 6: Final answer
    x = 523.65

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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.