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Finding the Fourth Proportional to 386.42, 579.62 and 129.92

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Solution

The fourth proportional to 386.42, 579.62 and 129.92 is: 194.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.42 : 579.62 = 129.92 : x
  2. Step 2: Convert to fraction form
    386.42/579.62 = 129.92/x
  3. Step 3: Cross multiply
    386.42x = 579.62 × 129.92
  4. Step 4: Simplify right side
    386.42x = 75,301.66
  5. Step 5: Solve for x
    x = 75,301.66/386.42
  6. Step 6: Final answer
    x = 194.87

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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.