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Finding the Fourth Proportional to 287.56, 396.81 and 163.21

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Solution

The fourth proportional to 287.56, 396.81 and 163.21 is: 225.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.56 : 396.81 = 163.21 : x
  2. Step 2: Convert to fraction form
    287.56/396.81 = 163.21/x
  3. Step 3: Cross multiply
    287.56x = 396.81 × 163.21
  4. Step 4: Simplify right side
    287.56x = 64,760.56
  5. Step 5: Solve for x
    x = 64,760.56/287.56
  6. Step 6: Final answer
    x = 225.21

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.