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Finding the Fourth Proportional to 779.82, 1,169.43 and 389.69

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Solution

The fourth proportional to 779.82, 1,169.43 and 389.69 is: 584.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.82 : 1,169.43 = 389.69 : x
  2. Step 2: Convert to fraction form
    779.82/1,169.43 = 389.69/x
  3. Step 3: Cross multiply
    779.82x = 1,169.43 × 389.69
  4. Step 4: Simplify right side
    779.82x = 455,716.64
  5. Step 5: Solve for x
    x = 455,716.64/779.82
  6. Step 6: Final answer
    x = 584.39

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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.