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Finding the Fourth Proportional to 779.20, 1,075.28 and 447.69

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Solution

The fourth proportional to 779.20, 1,075.28 and 447.69 is: 617.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    779.20 : 1,075.28 = 447.69 : x
  2. Step 2: Convert to fraction form
    779.20/1,075.28 = 447.69/x
  3. Step 3: Cross multiply
    779.20x = 1,075.28 × 447.69
  4. Step 4: Simplify right side
    779.20x = 481,390.98
  5. Step 5: Solve for x
    x = 481,390.98/779.20
  6. Step 6: Final answer
    x = 617.81

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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.