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Finding the Fourth Proportional to 406.14, 609.20 and 128.51

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Solution

The fourth proportional to 406.14, 609.20 and 128.51 is: 192.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.14 : 609.20 = 128.51 : x
  2. Step 2: Convert to fraction form
    406.14/609.20 = 128.51/x
  3. Step 3: Cross multiply
    406.14x = 609.20 × 128.51
  4. Step 4: Simplify right side
    406.14x = 78,288.29
  5. Step 5: Solve for x
    x = 78,288.29/406.14
  6. Step 6: Final answer
    x = 192.76

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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.