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Finding the Fourth Proportional to 811.17, 1,216.85 and 399.96

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Solution

The fourth proportional to 811.17, 1,216.85 and 399.96 is: 599.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.17 : 1,216.85 = 399.96 : x
  2. Step 2: Convert to fraction form
    811.17/1,216.85 = 399.96/x
  3. Step 3: Cross multiply
    811.17x = 1,216.85 × 399.96
  4. Step 4: Simplify right side
    811.17x = 486,691.33
  5. Step 5: Solve for x
    x = 486,691.33/811.17
  6. Step 6: Final answer
    x = 599.99

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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.