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Finding the Fourth Proportional to 1,211, 1,815.14 and 663

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Solution

The fourth proportional to 1,211, 1,815.14 and 663 is: 993.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,211 : 1,815.14 = 663 : x
  2. Step 2: Convert to fraction form
    1,211/1,815.14 = 663/x
  3. Step 3: Cross multiply
    1,211x = 1,815.14 × 663
  4. Step 4: Simplify right side
    1,211x = 1,203,437.82
  5. Step 5: Solve for x
    x = 1,203,437.82/1,211
  6. Step 6: Final answer
    x = 993.76

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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.