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Finding the Fourth Proportional to 408.12, 611.50 and 191.40

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Solution

The fourth proportional to 408.12, 611.50 and 191.40 is: 286.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.12 : 611.50 = 191.40 : x
  2. Step 2: Convert to fraction form
    408.12/611.50 = 191.40/x
  3. Step 3: Cross multiply
    408.12x = 611.50 × 191.40
  4. Step 4: Simplify right side
    408.12x = 117,041.10
  5. Step 5: Solve for x
    x = 117,041.10/408.12
  6. Step 6: Final answer
    x = 286.78

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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.