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Finding the Fourth Proportional to 83.69, 126.18 and 80.45

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Solution

The fourth proportional to 83.69, 126.18 and 80.45 is: 121.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.69 : 126.18 = 80.45 : x
  2. Step 2: Convert to fraction form
    83.69/126.18 = 80.45/x
  3. Step 3: Cross multiply
    83.69x = 126.18 × 80.45
  4. Step 4: Simplify right side
    83.69x = 10,151.18
  5. Step 5: Solve for x
    x = 10,151.18/83.69
  6. Step 6: Final answer
    x = 121.30

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.