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Finding the Fourth Proportional to 811.98, 1,218.11 and 285.04

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Solution

The fourth proportional to 811.98, 1,218.11 and 285.04 is: 427.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.98 : 1,218.11 = 285.04 : x
  2. Step 2: Convert to fraction form
    811.98/1,218.11 = 285.04/x
  3. Step 3: Cross multiply
    811.98x = 1,218.11 × 285.04
  4. Step 4: Simplify right side
    811.98x = 347,202.56
  5. Step 5: Solve for x
    x = 347,202.56/811.98
  6. Step 6: Final answer
    x = 427.60

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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.