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Finding the Fourth Proportional to 812.12, 1,218.31 and 292.30

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Solution

The fourth proportional to 812.12, 1,218.31 and 292.30 is: 438.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    812.12 : 1,218.31 = 292.30 : x
  2. Step 2: Convert to fraction form
    812.12/1,218.31 = 292.30/x
  3. Step 3: Cross multiply
    812.12x = 1,218.31 × 292.30
  4. Step 4: Simplify right side
    812.12x = 356,108.24
  5. Step 5: Solve for x
    x = 356,108.24/812.12
  6. Step 6: Final answer
    x = 438.49

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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.