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Finding the Fourth Proportional to 287.78, 397.11 and 163.45

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Solution

The fourth proportional to 287.78, 397.11 and 163.45 is: 225.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.78 : 397.11 = 163.45 : x
  2. Step 2: Convert to fraction form
    287.78/397.11 = 163.45/x
  3. Step 3: Cross multiply
    287.78x = 397.11 × 163.45
  4. Step 4: Simplify right side
    287.78x = 64,905.59
  5. Step 5: Solve for x
    x = 64,905.59/287.78
  6. Step 6: Final answer
    x = 225.54

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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.