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Finding the Fourth Proportional to 391.38, 587.00 and 208.68

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Solution

The fourth proportional to 391.38, 587.00 and 208.68 is: 312.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.38 : 587.00 = 208.68 : x
  2. Step 2: Convert to fraction form
    391.38/587.00 = 208.68/x
  3. Step 3: Cross multiply
    391.38x = 587.00 × 208.68
  4. Step 4: Simplify right side
    391.38x = 122,494.12
  5. Step 5: Solve for x
    x = 122,494.12/391.38
  6. Step 6: Final answer
    x = 312.98

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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.