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Finding the Fourth Proportional to 386.94, 580.30 and 213.58

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Solution

The fourth proportional to 386.94, 580.30 and 213.58 is: 320.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.94 : 580.30 = 213.58 : x
  2. Step 2: Convert to fraction form
    386.94/580.30 = 213.58/x
  3. Step 3: Cross multiply
    386.94x = 580.30 × 213.58
  4. Step 4: Simplify right side
    386.94x = 123,939.29
  5. Step 5: Solve for x
    x = 123,939.29/386.94
  6. Step 6: Final answer
    x = 320.30

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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.