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Finding the Fourth Proportional to 391.79, 587.45 and 206.84

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Solution

The fourth proportional to 391.79, 587.45 and 206.84 is: 310.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.79 : 587.45 = 206.84 : x
  2. Step 2: Convert to fraction form
    391.79/587.45 = 206.84/x
  3. Step 3: Cross multiply
    391.79x = 587.45 × 206.84
  4. Step 4: Simplify right side
    391.79x = 121,510.14
  5. Step 5: Solve for x
    x = 121,510.14/391.79
  6. Step 6: Final answer
    x = 310.14

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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.