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Finding the Fourth Proportional to 389.90, 584.08 and 206.84

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Solution

The fourth proportional to 389.90, 584.08 and 206.84 is: 309.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.90 : 584.08 = 206.84 : x
  2. Step 2: Convert to fraction form
    389.90/584.08 = 206.84/x
  3. Step 3: Cross multiply
    389.90x = 584.08 × 206.84
  4. Step 4: Simplify right side
    389.90x = 120,811.11
  5. Step 5: Solve for x
    x = 120,811.11/389.90
  6. Step 6: Final answer
    x = 309.85

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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.