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Finding the Fourth Proportional to 172.62, 258.54 and 81.18

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Solution

The fourth proportional to 172.62, 258.54 and 81.18 is: 121.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    172.62 : 258.54 = 81.18 : x
  2. Step 2: Convert to fraction form
    172.62/258.54 = 81.18/x
  3. Step 3: Cross multiply
    172.62x = 258.54 × 81.18
  4. Step 4: Simplify right side
    172.62x = 20,988.28
  5. Step 5: Solve for x
    x = 20,988.28/172.62
  6. Step 6: Final answer
    x = 121.59

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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.