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Finding the Fourth Proportional to 409.13, 613.31 and 189.78

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Solution

The fourth proportional to 409.13, 613.31 and 189.78 is: 284.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    409.13 : 613.31 = 189.78 : x
  2. Step 2: Convert to fraction form
    409.13/613.31 = 189.78/x
  3. Step 3: Cross multiply
    409.13x = 613.31 × 189.78
  4. Step 4: Simplify right side
    409.13x = 116,394.45
  5. Step 5: Solve for x
    x = 116,394.45/409.13
  6. Step 6: Final answer
    x = 284.49

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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.