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Finding the Fourth Proportional to 329.88, 491.31 and 320.80

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Solution

The fourth proportional to 329.88, 491.31 and 320.80 is: 477.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    329.88 : 491.31 = 320.80 : x
  2. Step 2: Convert to fraction form
    329.88/491.31 = 320.80/x
  3. Step 3: Cross multiply
    329.88x = 491.31 × 320.80
  4. Step 4: Simplify right side
    329.88x = 157,611.02
  5. Step 5: Solve for x
    x = 157,611.02/329.88
  6. Step 6: Final answer
    x = 477.78

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.