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Finding the Fourth Proportional to 821.61, 1,231.70 and 308.97

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Solution

The fourth proportional to 821.61, 1,231.70 and 308.97 is: 463.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.61 : 1,231.70 = 308.97 : x
  2. Step 2: Convert to fraction form
    821.61/1,231.70 = 308.97/x
  3. Step 3: Cross multiply
    821.61x = 1,231.70 × 308.97
  4. Step 4: Simplify right side
    821.61x = 380,556.80
  5. Step 5: Solve for x
    x = 380,556.80/821.61
  6. Step 6: Final answer
    x = 463.18

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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.