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Finding the Fourth Proportional to 519.81, 779.69 and 129.80

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Solution

The fourth proportional to 519.81, 779.69 and 129.80 is: 194.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    519.81 : 779.69 = 129.80 : x
  2. Step 2: Convert to fraction form
    519.81/779.69 = 129.80/x
  3. Step 3: Cross multiply
    519.81x = 779.69 × 129.80
  4. Step 4: Simplify right side
    519.81x = 101,206.04
  5. Step 5: Solve for x
    x = 101,206.04/519.81
  6. Step 6: Final answer
    x = 194.70

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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.