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Finding the Fourth Proportional to 77.81, 107.38 and 43.31

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Solution

The fourth proportional to 77.81, 107.38 and 43.31 is: 59.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.81 : 107.38 = 43.31 : x
  2. Step 2: Convert to fraction form
    77.81/107.38 = 43.31/x
  3. Step 3: Cross multiply
    77.81x = 107.38 × 43.31
  4. Step 4: Simplify right side
    77.81x = 4,650.95
  5. Step 5: Solve for x
    x = 4,650.95/77.81
  6. Step 6: Final answer
    x = 59.77

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.