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Finding the Fourth Proportional to 391.30, 586.82 and 208.59

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Solution

The fourth proportional to 391.30, 586.82 and 208.59 is: 312.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.30 : 586.82 = 208.59 : x
  2. Step 2: Convert to fraction form
    391.30/586.82 = 208.59/x
  3. Step 3: Cross multiply
    391.30x = 586.82 × 208.59
  4. Step 4: Simplify right side
    391.30x = 122,403.10
  5. Step 5: Solve for x
    x = 122,403.10/391.30
  6. Step 6: Final answer
    x = 312.81

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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.