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Finding the Fourth Proportional to 386.38, 579.84 and 213.18

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Solution

The fourth proportional to 386.38, 579.84 and 213.18 is: 319.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.38 : 579.84 = 213.18 : x
  2. Step 2: Convert to fraction form
    386.38/579.84 = 213.18/x
  3. Step 3: Cross multiply
    386.38x = 579.84 × 213.18
  4. Step 4: Simplify right side
    386.38x = 123,610.29
  5. Step 5: Solve for x
    x = 123,610.29/386.38
  6. Step 6: Final answer
    x = 319.92

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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.