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Finding the Fourth Proportional to 1,379.64, 2,069.49 and 513.78

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Solution

The fourth proportional to 1,379.64, 2,069.49 and 513.78 is: 770.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,379.64 : 2,069.49 = 513.78 : x
  2. Step 2: Convert to fraction form
    1,379.64/2,069.49 = 513.78/x
  3. Step 3: Cross multiply
    1,379.64x = 2,069.49 × 513.78
  4. Step 4: Simplify right side
    1,379.64x = 1,063,262.57
  5. Step 5: Solve for x
    x = 1,063,262.57/1,379.64
  6. Step 6: Final answer
    x = 770.68

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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.