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Finding the Fourth Proportional to 79.62, 109.85 and 56.31

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Solution

The fourth proportional to 79.62, 109.85 and 56.31 is: 77.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.62 : 109.85 = 56.31 : x
  2. Step 2: Convert to fraction form
    79.62/109.85 = 56.31/x
  3. Step 3: Cross multiply
    79.62x = 109.85 × 56.31
  4. Step 4: Simplify right side
    79.62x = 6,185.37
  5. Step 5: Solve for x
    x = 6,185.37/79.62
  6. Step 6: Final answer
    x = 77.69

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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.