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Finding the Fourth Proportional to 811.83, 1,219.76 and 519.47

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Solution

The fourth proportional to 811.83, 1,219.76 and 519.47 is: 780.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.83 : 1,219.76 = 519.47 : x
  2. Step 2: Convert to fraction form
    811.83/1,219.76 = 519.47/x
  3. Step 3: Cross multiply
    811.83x = 1,219.76 × 519.47
  4. Step 4: Simplify right side
    811.83x = 633,624.58
  5. Step 5: Solve for x
    x = 633,624.58/811.83
  6. Step 6: Final answer
    x = 780.49

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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.