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Finding the Fourth Proportional to 408.10, 611.40 and 191.20

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Solution

The fourth proportional to 408.10, 611.40 and 191.20 is: 286.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.10 : 611.40 = 191.20 : x
  2. Step 2: Convert to fraction form
    408.10/611.40 = 191.20/x
  3. Step 3: Cross multiply
    408.10x = 611.40 × 191.20
  4. Step 4: Simplify right side
    408.10x = 116,899.68
  5. Step 5: Solve for x
    x = 116,899.68/408.10
  6. Step 6: Final answer
    x = 286.45

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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.