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Finding the Fourth Proportional to 304.20, 419.31 and 221.31

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Solution

The fourth proportional to 304.20, 419.31 and 221.31 is: 305.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    304.20 : 419.31 = 221.31 : x
  2. Step 2: Convert to fraction form
    304.20/419.31 = 221.31/x
  3. Step 3: Cross multiply
    304.20x = 419.31 × 221.31
  4. Step 4: Simplify right side
    304.20x = 92,797.50
  5. Step 5: Solve for x
    x = 92,797.50/304.20
  6. Step 6: Final answer
    x = 305.05

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.