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Finding the Fourth Proportional to 79.71, 109.28 and 75.80

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Solution

The fourth proportional to 79.71, 109.28 and 75.80 is: 103.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.71 : 109.28 = 75.80 : x
  2. Step 2: Convert to fraction form
    79.71/109.28 = 75.80/x
  3. Step 3: Cross multiply
    79.71x = 109.28 × 75.80
  4. Step 4: Simplify right side
    79.71x = 8,282.50
  5. Step 5: Solve for x
    x = 8,282.50/79.71
  6. Step 6: Final answer
    x = 103.91

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.