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Finding the Fourth Proportional to 807.76, 1,209.21 and 518.59

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Solution

The fourth proportional to 807.76, 1,209.21 and 518.59 is: 776.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.76 : 1,209.21 = 518.59 : x
  2. Step 2: Convert to fraction form
    807.76/1,209.21 = 518.59/x
  3. Step 3: Cross multiply
    807.76x = 1,209.21 × 518.59
  4. Step 4: Simplify right side
    807.76x = 627,084.21
  5. Step 5: Solve for x
    x = 627,084.21/807.76
  6. Step 6: Final answer
    x = 776.32

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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.