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Finding the Fourth Proportional to 391.37, 586.89 and 208.71

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Solution

The fourth proportional to 391.37, 586.89 and 208.71 is: 312.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.37 : 586.89 = 208.71 : x
  2. Step 2: Convert to fraction form
    391.37/586.89 = 208.71/x
  3. Step 3: Cross multiply
    391.37x = 586.89 × 208.71
  4. Step 4: Simplify right side
    391.37x = 122,489.81
  5. Step 5: Solve for x
    x = 122,489.81/391.37
  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.