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Finding the Fourth Proportional to 79.91, 119.79 and 28.55

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Solution

The fourth proportional to 79.91, 119.79 and 28.55 is: 42.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    79.91 : 119.79 = 28.55 : x
  2. Step 2: Convert to fraction form
    79.91/119.79 = 28.55/x
  3. Step 3: Cross multiply
    79.91x = 119.79 × 28.55
  4. Step 4: Simplify right side
    79.91x = 3,420.00
  5. Step 5: Solve for x
    x = 3,420.00/79.91
  6. Step 6: Final answer
    x = 42.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.