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Finding the Fourth Proportional to 821.41, 1,231.71 and 743.65

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Solution

The fourth proportional to 821.41, 1,231.71 and 743.65 is: 1,115.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.41 : 1,231.71 = 743.65 : x
  2. Step 2: Convert to fraction form
    821.41/1,231.71 = 743.65/x
  3. Step 3: Cross multiply
    821.41x = 1,231.71 × 743.65
  4. Step 4: Simplify right side
    821.41x = 915,961.14
  5. Step 5: Solve for x
    x = 915,961.14/821.41
  6. Step 6: Final answer
    x = 1,115.11

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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.