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Finding the Fourth Proportional to 774.80, 1,069.23 and 420.73

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Solution

The fourth proportional to 774.80, 1,069.23 and 420.73 is: 580.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    774.80 : 1,069.23 = 420.73 : x
  2. Step 2: Convert to fraction form
    774.80/1,069.23 = 420.73/x
  3. Step 3: Cross multiply
    774.80x = 1,069.23 × 420.73
  4. Step 4: Simplify right side
    774.80x = 449,857.14
  5. Step 5: Solve for x
    x = 449,857.14/774.80
  6. Step 6: Final answer
    x = 580.61

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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.