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Finding the Fourth Proportional to 391.42, 586.65 and 208.54

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Solution

The fourth proportional to 391.42, 586.65 and 208.54 is: 312.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.42 : 586.65 = 208.54 : x
  2. Step 2: Convert to fraction form
    391.42/586.65 = 208.54/x
  3. Step 3: Cross multiply
    391.42x = 586.65 × 208.54
  4. Step 4: Simplify right side
    391.42x = 122,339.99
  5. Step 5: Solve for x
    x = 122,339.99/391.42
  6. Step 6: Final answer
    x = 312.55

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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.