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Finding the Fourth Proportional to 386.87, 579.78 and 213.53

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Solution

The fourth proportional to 386.87, 579.78 and 213.53 is: 320.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    386.87 : 579.78 = 213.53 : x
  2. Step 2: Convert to fraction form
    386.87/579.78 = 213.53/x
  3. Step 3: Cross multiply
    386.87x = 579.78 × 213.53
  4. Step 4: Simplify right side
    386.87x = 123,797.52
  5. Step 5: Solve for x
    x = 123,797.52/386.87
  6. Step 6: Final answer
    x = 320.00

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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.