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Finding the Fourth Proportional to 287.90, 397.31 and 163.56

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Solution

The fourth proportional to 287.90, 397.31 and 163.56 is: 225.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.90 : 397.31 = 163.56 : x
  2. Step 2: Convert to fraction form
    287.90/397.31 = 163.56/x
  3. Step 3: Cross multiply
    287.90x = 397.31 × 163.56
  4. Step 4: Simplify right side
    287.90x = 64,984.02
  5. Step 5: Solve for x
    x = 64,984.02/287.90
  6. Step 6: Final answer
    x = 225.72

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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.