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Finding the Fourth Proportional to 386.69, 579.50 and 213.09

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Solution

The fourth proportional to 386.69, 579.50 and 213.09 is: 319.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.69 : 579.50 = 213.09 : x
  2. Step 2: Convert to fraction form
    386.69/579.50 = 213.09/x
  3. Step 3: Cross multiply
    386.69x = 579.50 × 213.09
  4. Step 4: Simplify right side
    386.69x = 123,487.82
  5. Step 5: Solve for x
    x = 123,487.82/386.69
  6. Step 6: Final answer
    x = 319.35

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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.