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Finding the Fourth Proportional to 1,289.87, 1,922.11 and 1,211.95

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Solution

The fourth proportional to 1,289.87, 1,922.11 and 1,211.95 is: 1,805.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.87 : 1,922.11 = 1,211.95 : x
  2. Step 2: Convert to fraction form
    1,289.87/1,922.11 = 1,211.95/x
  3. Step 3: Cross multiply
    1,289.87x = 1,922.11 × 1,211.95
  4. Step 4: Simplify right side
    1,289.87x = 2,329,485.54
  5. Step 5: Solve for x
    x = 2,329,485.54/1,289.87
  6. Step 6: Final answer
    x = 1,805.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.