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Finding the Fourth Proportional to 321.90, 480.90 and 205.36

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Solution

The fourth proportional to 321.90, 480.90 and 205.36 is: 306.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.90 : 480.90 = 205.36 : x
  2. Step 2: Convert to fraction form
    321.90/480.90 = 205.36/x
  3. Step 3: Cross multiply
    321.90x = 480.90 × 205.36
  4. Step 4: Simplify right side
    321.90x = 98,757.19
  5. Step 5: Solve for x
    x = 98,757.19/321.90
  6. Step 6: Final answer
    x = 306.80

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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.