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Finding the Fourth Proportional to 811.47, 1,216.18 and 518.86

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Solution

The fourth proportional to 811.47, 1,216.18 and 518.86 is: 777.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.47 : 1,216.18 = 518.86 : x
  2. Step 2: Convert to fraction form
    811.47/1,216.18 = 518.86/x
  3. Step 3: Cross multiply
    811.47x = 1,216.18 × 518.86
  4. Step 4: Simplify right side
    811.47x = 631,027.15
  5. Step 5: Solve for x
    x = 631,027.15/811.47
  6. Step 6: Final answer
    x = 777.63

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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.