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Finding the Fourth Proportional to 386.92, 579.60 and 215.56

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Solution

The fourth proportional to 386.92, 579.60 and 215.56 is: 322.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.92 : 579.60 = 215.56 : x
  2. Step 2: Convert to fraction form
    386.92/579.60 = 215.56/x
  3. Step 3: Cross multiply
    386.92x = 579.60 × 215.56
  4. Step 4: Simplify right side
    386.92x = 124,938.58
  5. Step 5: Solve for x
    x = 124,938.58/386.92
  6. Step 6: Final answer
    x = 322.91

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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.