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Finding the Fourth Proportional to 321.40, 481.88 and 218.90

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Solution

The fourth proportional to 321.40, 481.88 and 218.90 is: 328.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    321.40 : 481.88 = 218.90 : x
  2. Step 2: Convert to fraction form
    321.40/481.88 = 218.90/x
  3. Step 3: Cross multiply
    321.40x = 481.88 × 218.90
  4. Step 4: Simplify right side
    321.40x = 105,485.28
  5. Step 5: Solve for x
    x = 105,485.28/321.40
  6. Step 6: Final answer
    x = 328.20

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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.