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Finding the Fourth Proportional to 408.55, 611.75 and 215.59

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Solution

The fourth proportional to 408.55, 611.75 and 215.59 is: 322.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.55 : 611.75 = 215.59 : x
  2. Step 2: Convert to fraction form
    408.55/611.75 = 215.59/x
  3. Step 3: Cross multiply
    408.55x = 611.75 × 215.59
  4. Step 4: Simplify right side
    408.55x = 131,886.10
  5. Step 5: Solve for x
    x = 131,886.10/408.55
  6. Step 6: Final answer
    x = 322.82

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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.