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Finding the Fourth Proportional to 1,069.80, 1,604.22 and 420.09

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Solution

The fourth proportional to 1,069.80, 1,604.22 and 420.09 is: 629.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,069.80 : 1,604.22 = 420.09 : x
  2. Step 2: Convert to fraction form
    1,069.80/1,604.22 = 420.09/x
  3. Step 3: Cross multiply
    1,069.80x = 1,604.22 × 420.09
  4. Step 4: Simplify right side
    1,069.80x = 673,916.78
  5. Step 5: Solve for x
    x = 673,916.78/1,069.80
  6. Step 6: Final answer
    x = 629.95

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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.