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Finding the Fourth Proportional to 393.91, 587.80 and 391.65

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Solution

The fourth proportional to 393.91, 587.80 and 391.65 is: 584.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    393.91 : 587.80 = 391.65 : x
  2. Step 2: Convert to fraction form
    393.91/587.80 = 391.65/x
  3. Step 3: Cross multiply
    393.91x = 587.80 × 391.65
  4. Step 4: Simplify right side
    393.91x = 230,211.87
  5. Step 5: Solve for x
    x = 230,211.87/393.91
  6. Step 6: Final answer
    x = 584.43

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.