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Finding the Fourth Proportional to 83.12, 115.28 and 80.36

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Solution

The fourth proportional to 83.12, 115.28 and 80.36 is: 111.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    83.12 : 115.28 = 80.36 : x
  2. Step 2: Convert to fraction form
    83.12/115.28 = 80.36/x
  3. Step 3: Cross multiply
    83.12x = 115.28 × 80.36
  4. Step 4: Simplify right side
    83.12x = 9,263.90
  5. Step 5: Solve for x
    x = 9,263.90/83.12
  6. Step 6: Final answer
    x = 111.45

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.