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Finding the Fourth Proportional to 1,039.90, 1,559.40 and 519.70

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Solution

The fourth proportional to 1,039.90, 1,559.40 and 519.70 is: 779.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,039.90 : 1,559.40 = 519.70 : x
  2. Step 2: Convert to fraction form
    1,039.90/1,559.40 = 519.70/x
  3. Step 3: Cross multiply
    1,039.90x = 1,559.40 × 519.70
  4. Step 4: Simplify right side
    1,039.90x = 810,420.18
  5. Step 5: Solve for x
    x = 810,420.18/1,039.90
  6. Step 6: Final answer
    x = 779.33

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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.