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Finding the Fourth Proportional to 328.20, 491.81 and 219.80

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Solution

The fourth proportional to 328.20, 491.81 and 219.80 is: 329.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.20 : 491.81 = 219.80 : x
  2. Step 2: Convert to fraction form
    328.20/491.81 = 219.80/x
  3. Step 3: Cross multiply
    328.20x = 491.81 × 219.80
  4. Step 4: Simplify right side
    328.20x = 108,096.28
  5. Step 5: Solve for x
    x = 108,096.28/328.20
  6. Step 6: Final answer
    x = 329.36

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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.