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Finding the Fourth Proportional to 386.75, 580.13 and 215.75

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Solution

The fourth proportional to 386.75, 580.13 and 215.75 is: 323.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.75 : 580.13 = 215.75 : x
  2. Step 2: Convert to fraction form
    386.75/580.13 = 215.75/x
  3. Step 3: Cross multiply
    386.75x = 580.13 × 215.75
  4. Step 4: Simplify right side
    386.75x = 125,161.97
  5. Step 5: Solve for x
    x = 125,161.97/386.75
  6. Step 6: Final answer
    x = 323.63

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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.