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Finding the Fourth Proportional to 321.47, 445.80 and 308.21

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Solution

The fourth proportional to 321.47, 445.80 and 308.21 is: 427.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.47 : 445.80 = 308.21 : x
  2. Step 2: Convert to fraction form
    321.47/445.80 = 308.21/x
  3. Step 3: Cross multiply
    321.47x = 445.80 × 308.21
  4. Step 4: Simplify right side
    321.47x = 137,398.94
  5. Step 5: Solve for x
    x = 137,398.94/321.47
  6. Step 6: Final answer
    x = 427.41

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.