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Finding the Fourth Proportional to 77.79, 107.36 and 42.82

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Solution

The fourth proportional to 77.79, 107.36 and 42.82 is: 59.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    77.79 : 107.36 = 42.82 : x
  2. Step 2: Convert to fraction form
    77.79/107.36 = 42.82/x
  3. Step 3: Cross multiply
    77.79x = 107.36 × 42.82
  4. Step 4: Simplify right side
    77.79x = 4,597.27
  5. Step 5: Solve for x
    x = 4,597.27/77.79
  6. Step 6: Final answer
    x = 59.10

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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.