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Finding the Fourth Proportional to 1,379.70, 1,903.80 and 819.97

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Solution

The fourth proportional to 1,379.70, 1,903.80 and 819.97 is: 1,131.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.70 : 1,903.80 = 819.97 : x
  2. Step 2: Convert to fraction form
    1,379.70/1,903.80 = 819.97/x
  3. Step 3: Cross multiply
    1,379.70x = 1,903.80 × 819.97
  4. Step 4: Simplify right side
    1,379.70x = 1,561,049.37
  5. Step 5: Solve for x
    x = 1,561,049.37/1,379.70
  6. Step 6: Final answer
    x = 1,131.44

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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.