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Finding the Fourth Proportional to 80.37, 121.12 and 71.28

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Solution

The fourth proportional to 80.37, 121.12 and 71.28 is: 107.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    80.37 : 121.12 = 71.28 : x
  2. Step 2: Convert to fraction form
    80.37/121.12 = 71.28/x
  3. Step 3: Cross multiply
    80.37x = 121.12 × 71.28
  4. Step 4: Simplify right side
    80.37x = 8,633.26
  5. Step 5: Solve for x
    x = 8,633.26/80.37
  6. Step 6: Final answer
    x = 107.42

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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.