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Finding the Fourth Proportional to 80.28, 120.38 and 28.91

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Solution

The fourth proportional to 80.28, 120.38 and 28.91 is: 43.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.28 : 120.38 = 28.91 : x
  2. Step 2: Convert to fraction form
    80.28/120.38 = 28.91/x
  3. Step 3: Cross multiply
    80.28x = 120.38 × 28.91
  4. Step 4: Simplify right side
    80.28x = 3,480.19
  5. Step 5: Solve for x
    x = 3,480.19/80.28
  6. Step 6: Final answer
    x = 43.35

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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.