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Finding the Fourth Proportional to 391.13, 586.57 and 208.42

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Solution

The fourth proportional to 391.13, 586.57 and 208.42 is: 312.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.13 : 586.57 = 208.42 : x
  2. Step 2: Convert to fraction form
    391.13/586.57 = 208.42/x
  3. Step 3: Cross multiply
    391.13x = 586.57 × 208.42
  4. Step 4: Simplify right side
    391.13x = 122,252.92
  5. Step 5: Solve for x
    x = 122,252.92/391.13
  6. Step 6: Final answer
    x = 312.56

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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.