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Finding the Fourth Proportional to 172.89, 259.28 and 81.63

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Solution

The fourth proportional to 172.89, 259.28 and 81.63 is: 122.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.89 : 259.28 = 81.63 : x
  2. Step 2: Convert to fraction form
    172.89/259.28 = 81.63/x
  3. Step 3: Cross multiply
    172.89x = 259.28 × 81.63
  4. Step 4: Simplify right side
    172.89x = 21,164.62
  5. Step 5: Solve for x
    x = 21,164.62/172.89
  6. Step 6: Final answer
    x = 122.42

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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.