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Finding the Fourth Proportional to 812.24, 1,218 and 778.64

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Solution

The fourth proportional to 812.24, 1,218 and 778.64 is: 1,167.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.24 : 1,218 = 778.64 : x
  2. Step 2: Convert to fraction form
    812.24/1,218 = 778.64/x
  3. Step 3: Cross multiply
    812.24x = 1,218 × 778.64
  4. Step 4: Simplify right side
    812.24x = 948,383.52
  5. Step 5: Solve for x
    x = 948,383.52/812.24
  6. Step 6: Final answer
    x = 1,167.61

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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.