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Finding the Fourth Proportional to 408.40, 611.82 and 253.60

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Solution

The fourth proportional to 408.40, 611.82 and 253.60 is: 379.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.40 : 611.82 = 253.60 : x
  2. Step 2: Convert to fraction form
    408.40/611.82 = 253.60/x
  3. Step 3: Cross multiply
    408.40x = 611.82 × 253.60
  4. Step 4: Simplify right side
    408.40x = 155,157.55
  5. Step 5: Solve for x
    x = 155,157.55/408.40
  6. Step 6: Final answer
    x = 379.92

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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.