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Finding the Fourth Proportional to 821.09, 1,231.79 and 265.95

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Solution

The fourth proportional to 821.09, 1,231.79 and 265.95 is: 398.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.09 : 1,231.79 = 265.95 : x
  2. Step 2: Convert to fraction form
    821.09/1,231.79 = 265.95/x
  3. Step 3: Cross multiply
    821.09x = 1,231.79 × 265.95
  4. Step 4: Simplify right side
    821.09x = 327,595.22
  5. Step 5: Solve for x
    x = 327,595.22/821.09
  6. Step 6: Final answer
    x = 398.97

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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.