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Finding the Fourth Proportional to 79.39, 109.56 and 58.78

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Solution

The fourth proportional to 79.39, 109.56 and 58.78 is: 81.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.39 : 109.56 = 58.78 : x
  2. Step 2: Convert to fraction form
    79.39/109.56 = 58.78/x
  3. Step 3: Cross multiply
    79.39x = 109.56 × 58.78
  4. Step 4: Simplify right side
    79.39x = 6,439.94
  5. Step 5: Solve for x
    x = 6,439.94/79.39
  6. Step 6: Final answer
    x = 81.12

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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.